diagnosing a headgasket failure

i wanted to make sure that i have a head gasket failure this is what i,ve done. i searched the entire block and head gskt nothing there. i pressure tested the system to 18 lbs slight leak in a heater hose fixed that. there is no coolant in the oil. my nose doesnt work that good these days so i cant smell any coolant from the exhaust. no white smoke from exhaust i pulled the plugs today 1 was kinda black and the rest were white? i add a cup or so of coolant a day, so where is it going??? and lastly a head gskt kit who do you buy from. i did this job 4 years ago on a different van using a felpro kit that the machine shop sold me it worked fine. but i keep reading use only toyota. my goal is to try n nurse it through the winter cuz i dont have a garage and i need the van for my heating service. any thoughts? thanx in advance joe g

To save some time, here's a copy/paste from another thread on this forum:

Quote:

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Originally Posted by timsrv

Head gaskets can blow in different ways. It all depends on what part of the gasket or mating surface is damaged. There are several ports where oil and coolant travel between the head and the block. Then theres the cylinders and they contain high pressure combustion gases. The head gasket's job is to seal all these areas and keep them separated from each other. If the gasket and/or the mating surfaces become damaged between an oil and a coolant port, then these two fluids can mix creating a milky brown foam in the oil pan. Oil can also enter your cooling system and should be evident when you look into the radiator fill port (oil will float on top of the coolant).

Sometimes the leak can occur between a cylinder and a coolant port. When this happens combustion gases can pass into the cooling system and depending on the severity of the leak, the combustion pressure can force coolant out of the cooling system overflow (this leads to overheating). Sometimes coolant leaks into a cylinder and is expelled through the exhaust in the form of steam. In severe cases coolant can leak into a cylinder after shut-down and hydro-lock the engine.

Sometimes the gasket can blow between cylinders. When that happens the end result is 2 cylinders next to each other that have low or non-existent compression. If the van runs at all it will have severe performance problems and/or exhibit a very bad miss.

Sometimes the gasket can blow allowing coolant to leak externally. This type of blown gasket simply causes your van to lose coolant and depending on the severity it can still be used like this for extended periods (assuming you keep the coolant levels topped off). I have been experiencing this type of head gasket failure (for over a year now) but the severity of the breach isn't terrible, so I continue to top off the coolant every couple of weeks. I also get to look at a small puddle of coolant on my garage floor every morning when I leave for work (I need to fix this one of these days).

So, to sum things up, your head gasket can fail in any one of these ways or a combination of 2 or more ways at the same time. Based on the fact you are getting coolant in your oil I'd say your problem is the 1st one type outlined. Of course it could also be a crack in your head or block, but by far having the head gasket fail is most common.

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Depending on how much you drive, 1 cup per week can be a very small leak and as you know small leaks can be hard to find. On these vans there are several places that leaks can occur undetected. To find a leak of this size you may need to invest in some tools and spend some time troubleshooting. Coolant leaks are often intermittent (some leaks occur only when cold, some only when hot, and some only in transition between hot & cold). Before condemning the head gasket, I would gain as much access as possible by putting on jack stands and removing the passenger seat / engine access panels. When the van is stone cold, pressurize the system to around 15psi using a testing device (see picture below).
http://i8.photobucket.com/albums/a23...m/IMG_0616.jpg

Note: This type of hand pump/testing device is easy to find for purchase but may also be available for renting at a larger auto parts store. If you're thinking of buying, even Amazon has these http://www.amazon.com/Stant-12270-Co...5318080&sr=8-1.

Let the van sit for about 15 minutes while monitoring pressure then begin a careful inspection of the radiator, heater core areas, and any possible place that coolant could be externally leaking. If the van holds pressure for 1/2 hr or more with no detectable leaks, then start the engine and continue your inspection as it's warming up. WARNING: Be very careful of moving parts (like the fan/belts/pulleys) and hot exhaust!. Keep in mind that while the pressure pump is on the van will not automatically vent pressure, so you will need to monitor and manually adjust pressure during the test. All of these testers have a manual pressure relief valve on them so use it as necessary.

I'm guessing you will find it before the van reaches normal operating temperature, but if nothing leaks during this time I might start to suspect a head gasket problem. Note: While checking for leaks be sure to monitor the small 8mm heater hoses by the throttle body and the infamous "hoses of death" outlined in THIS THREAD. Also use a flash-light and a mirror to check the side of the block under the exhaust manifold (see example of leak below).
http://i8.photobucket.com/albums/a23...psc661bc0e.jpg

Assuming you still haven't found it, and you are now convinced it's just got to be a head gasket, it's time to do an HC test of your cooling system. For this you will need to take the van into a mechanic with the proper test equipment or you can buy a "do it yourself" test kit at Napa. Napa sells a chemical tester for about $40 and you can test for this yourself. This kit includes a test tube like device and a bottle of blue chemical. You put the chemical in the test tube and hold it over the top of your filler neck while the engine is running. Then you take a bulb (also included in the kit) and use it to suck air/steam from the filler neck. If combustion gasses are present the chemical will change to yellow. If it fails that test, then you know it's the head gasket

A couple of tips worth noting. A careful visual inspection can often reveal the source of the leak even when it's not leaking. Keep your eyes peeled for green/greenish blue residue and crystals on or around anything that could be leaking. Your water pump is mounted to the timing cover and coolant can leak from behind the timing cover..........so check there too. Also, our overflow bottles have a level sensor in the bottom and these themselves can leak..........so check around this area too. The rear heater core is right behind the passenger side front tire, so be sure to check that area as well. With the engine off, grab your radiator fan and try to wiggle it back & forth. Sometimes the water pump will wear out and coolant will leak out the shaft. If the shaft is loose (wiggles side to side), then that's a dead give-away. There is a "weep hole" in the bottom front of the water pump housing and sometimes the coolant can drip out here and be slung about by the fan pulley. With the heat of the engine compartment this can cause the coolant to evaporate before it drips to the ground. Happy hunting and keep us posted on what you find. Tim

PS: If you end up diagnosing a failed head gasket, Here's a post that should help you make that repair: http://www.toyotavantech.com/forum/s...=3009#post3009

wow tim that was an excelent read !! i think i,m gonna go with the chemical test. i spoke with a wrench friend and he has that testing kit. i spect i,ll start squirelling all the lil things that i,ll need and go ahead and do this job. if i grovel good enough i can prolly get some garage space in 1 of 3 places. thanx so much for the informative reply. till then i,m just gonna quench the beast and wish for the best!! thanx again

No problem Joe. The "cold to hot" leak test can also be done without the pressure tester. The tester simply increases your chances of finding the leak.

As for your gasket question, I'm sure there are other gaskets (besides Toyota) that are good too. The problem is not knowing which ones they are. From what I understand there are some out there that don't even have all the passage holes in the correct spots. Considering the time and expense of doing this job I'd consider it too big of a risk to purchase an aftermarket kit. Toyota sells a "valve grind kit" Part #04112-73035 for about $95 (if you purchase from a discount internet site like www.1stToyotaParts.com). That kit includes the head gasket and every other gasket/seal you will need for the job (so it really isn't that expensive).

PS: I re-read your original post and see it leaks about a cup per day (not per week). That's even better from a troubleshooting perspective (makes it easier to find). Good luck. Tim

:whs:

+1 to Tim's suggestions. Tracking a coolant leak is a real pain, but a LOT cheaper and easier than a head job or an engine swap ... and soooo much better than doing one or both of those jobs only to have it still leak when you're done.

1 cup per day sounds like a lot to be losing without also seeing other performance symptoms ... unless it really is just a leak. Your single black plug may be oil-fouled; leaking spark plug o-rings are not uncommon (usually cylinder 1).

If the block and engine bay aren't squeaky clean, start with that first. Coolant on top of oil looks like oil, for instance. Coolant on top of semi-greasy dust looks like oil too. (Go ahead, ask me how I know ...)

If you want to give it a go without pressurizing, run the van (try to stay out of the mud and puddles) and then look around with an LED flashlight. At least some green coolants will show up very strongly in the LED light (to increase the contrast, don't use other light in the engine bay). I have located more than one tiny pinhole in a coolant hose that way.

Also consider that one or more of the coolant PIPES may be leaking. The one alongside the drivers' side of the engine block is a common culprit, although hard to see from above.

If you are still seeing coolant sprayed all over by the fan, think "water pump" and "radiator" as well as "local" hoses.

A small breach in the hose from the filler neck to the overflow tank can keep the van from sucking coolant out of the tank the way it's supposed to, and also suck air into the system which makes it want to boil over. (Um, ask me how I learned THAT, too).

A bad radiator cap can cause coolant loss at the filler neck (again, personal experience).

If you have A/C, have you dropped the condenser and inspected all the heater hoses (and front heater valve) hiding "underneath" (actually above) it?

Lots to look at !!!

FWIW, I've driven a van with a BHG and it didn't use anywhere near 1c per day (my commute is 40-50 miles). OTOH, I am waiting for better weather to tackle a coolant pipe leak in one of spouse's vans ... and that one IS using around 1c per day. Food for thought ...

Gwen

hi again i dont want to bore you guys with my problem but, i think this could be a signal as to what is happening with the primer van. just for a hunch i decieded to insert this plastic bottle that tennis balls come in. it mounts nice in front of the expantion tank. so after a week or less of adding coolant to the gooseneck i find now that the expantion tank has filled up and now it is over flowing into the tennis ball tank?? hummm. this tells me that there is a problem somewhere else instead of a cracked head gasket.... i think i hope. in short the coolant is being sent back to the tank and when full it would just shoot out. i did look in trouble shooting the cooling system but didnt find what i needed to hear. so i,m counting on you guyz to set me straight on why the coolant is being forced back to the expantion tank.

Just for clarification I want to talk about the way the system is supposed to work. Normally you would top off the fill port on the engine, then fill the recovery tank somewhere between the "full" lines (never fill it to the top). When the engine warms up the coolant expands. As it expands it forces it's way past the radiator cap and into the recovery tank (usually about a cup or so). After shut-down the engine cools and a vacuum forms as the coolant contracts. This vacuum allows the system to suck the coolant back from the recovery tank. In order for this to work the return hoses must be in good shape (free from leaks or holes) and must extend to the bottom of the recovery tank (via the little hose that attaches to the interior of the lid). If there are any holes or leaks in any part of the recovery tank hose system then it will not function correctly. If a hose has a hole in it, it will still move coolant from the engine to the tank, but will not suck it back to the engine. This is because liquid transfer via suction is much more sensitive than transfer by pressure (just try to use a straw with a hole to suck a milkshake).

Assuming your recovery system hoses are in good shape, the only other thing that can force coolant out of the bottle is excessive pressure in the coolant system. Excessive pressure can be a result of a blown head gasket or a cracked head. It sounds to me like it's time to do an HC test of your cooling system. Tim

thanx for comming back with that tip. i,ll check the hoses tomorrow. i guessing that the hoses will be fine. because i do heating repairs i cant take the van off the road till it warms up a lil bit. i think i mentioned this before that i have performed the headgasket repair on my other van and i,m not too intiminated by it.i have already started soakin in the pb blaster to some of the rusty stuff with the intent of easy removal!! i was thinkin that i was gonna get lucky like a bad cap or bad thermostat but i guess not that lucky. thanx again tim yer help is greatly appreciated.

Just thought I'd chime in on the topic of gasket manufacturers.

I used a Fel-Pro valve/grind kit from my local distributor and haven't had a problem (22,000km/13,670mi on it so far.) Obviously OEM is always best for ease of mind -- just don't feel worried about the Fel-Pro kit. Its solid. (Now if you bought a kit for $20 on Ebay... then I'd be worried.)

I used to use Fel-Pro Permatorque gaskets exclusively back in the 80's & early 90's when I was building the high performance V-8 engines. Never had a problem, but then again these were cast iron heads on cast iron blocks. There's a lot more stress on the gasket with an aluminum head, but who's to say which is better. I just know that Toyota knows their products better than anybody else. Also, I'm not sure about Brand X, but I know Toyota will often monitor their own products and make improvements when patterns of failure emerge. Back when I worked for the dealer we were always seeing upgrades and changes on high failure parts. When I did the head-gasket on my Previa a few years back I noticed the new gasket had more steel reinforcement than the original. Things like that make me feel good about buying genuine Toyota. Then there's the argument of "if a Toyota gasket blows on a Toyota engine, then there's nobody to blame except for Toyota" (the buck stops with them). If the failed part is brand X, then it's hard to say where the fault lies. Of course brand X will probably blame it on the mechanic or a bad Toyota design :doh:. Toyota wants their products to maintain a stellar reputation & brand X might not care. Of course this is all just talk, I say go with the brand you trust, because if it fails again, ultimately it will be your problem :cry:. I think Fel-Pro products are probably a safe bet. Tim

Hi everyone, I found this thread when looking for solutions on my overheating van. As per mentioned above, I'm planning to re-do a leak test all over the engine/hoses and probably next test a for a blown head gasket.

In the meantime, I wanted to ask you guys whether you also experienced LOTS of bubbles when starting your van in cold without the radiator cap (and yes, they increase when revs do). In order to save time, could this be a confirmed signal of a BHG?

Thanks in advance!

I don't think the bubbles necessarily mean a blown head gasket and can be normal. I had lots of coolant bubbles that increased with RPMs (and some residual oil in coolant) after replacing my head gasket and freaked out that I hadn't fixed the problem. I got a $40 coolant exhaust gas tester and did a compression test to rule out if the bubbles were the result of a bad HG.

1987 Toyota Van 4WD Auto 178k with a 47k engineI can do trips around town maybe up to 40-50 miles its fine. Longer trips or under load/hills, it will overheat.
I get large coolant loss through the overflow reservoir.
No leaks that I can find elsewhere, HOD and most coolant hoses replaced, thermostat, aisin waterpump & fan clutch, radiator cap were all replaced within the last year.


Mechanic did pressure test, it holds pressure fine while running 30-40mins. its only under load that I'm getting overheating or coolant loss.


Leaning toward headgasket - mechanic did chemical test and that didn't show failure, although i've read that they don't always work...


Last oil change i did i saw a small amount of tiny bubbles of coolant?? at the very bottom of the waste oil...this could be paranoia?


I do most work myself but leave bigger jobs (like headgasket!) to a trusted mechanic. He is happy to work on the van but not particularly knowledgeable about them.


Is there anything else we should be looking for before pulling the trigger on head gasket replacement?

Tim and Gwen have given good advice above for chasing down cooling system problems; obviously you'd want to rule any of these out (and ideally get a test for a failed HG) before commencing with a head gasket replacement. I have found something as simple as a bad radiator cap can cause overheating and overflow of the coolant reservoir. It doesn't sound like you are losing coolant other than boiling out through the reservoir? Sounds like you've done a lot of cooling system parts replacement already, but have you checked the condition of the radiator itself? Maybe it's plugged up and just needs to be rodded/recored to restore cooling performance. Plenty of threads here about radiator repairs and auxiliary radiators. Or there could be blockage elsewhere in the cooling system?

Chemical HG test didn't show any issues. Pressure test of system didn't show any issues either (radiator cap was rated a little low so that was replaced but didn't solve anything). I have a very small loss of coolant through the radiator petcock.
Most recent flush was done when I replaced the waterpump and t-stat, the flush looked cleaned.

I've read quite a few threads with similar symptoms ultimately being small HG leak. so i was looking for input before pulling the trigger.

What is the best way to check the radiator in our vans? Run the van without the fan shroud and try to keep away from the fan when checking for cool spots?

Or, Should I pull the radiator and flush it?

If you pull the top radiator hose and look in there with a flashlight you can view a small portion of the core where it attaches to the tank. If it looks clean and clear, then that's a good indication the radiator is "probably" okay. If however you see a lot of build-up of crud/incrustation, that's a good indication it needs professional help. You can also use an infrared thermometer on the radiator with the shroud removed, but it can be hard to get a conclusive diagnostic as flow through the radiator depends on demand from the engine t-stat (so flow will vary). If in doubt, take it in for service as that's far easier than doing a head gasket. Besides, it's no youngster so not a bad idea to have it's condition verified every 30 years or so :)>:. Tim

PS: Look at it this way. Even if it is a head gasket and you end up doing that, you would want to know the radiator was in good shape before running it again. Getting the radiator checked out by a professional is just good insurance. Who knows, it may even solve your problem.

Quote:

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Originally Posted by BelueJacques

Chemical HG test didn't show any issues. Pressure test of system didn't show any issues either (radiator cap was rated a little low so that was replaced but didn't solve anything). I have a very small loss of coolant through the radiator petcock.
Most recent flush was done when I replaced the waterpump and t-stat, the flush looked cleaned.

I've read quite a few threads with similar symptoms ultimately being small HG leak. so i was looking for input before pulling the trigger.

What is the best way to check the radiator in our vans? Run the van without the fan shroud and try to keep away from the fan when checking for cool spots?

Or, Should I pull the radiator and flush it?

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...I'd double check the fan clutch before going too far. Recently I got a brand new Aisen, it never actually free wheeled or let me get up to running temperature. Perhaps it can be that a new fan clutch doesn't work in the other regard of actually engaging when things get hot.

For the effort and expense of a head job, I would suggest that you keep on going until you're certain of the issue. I don't think it's a case that you would do more damage for keeping going.

Flushed both heater cores both ways and they looked great. Pulled top radiator hose and what I can see (not much) does look completely clean. I’ve got a small amount of corrosion on the outside of the radiator, but flushes look clean.

My aisin clutch fan runs on start up but I wouldn’t say it ever really “roars”. It’s easy enough to replace and I got an extra - so I’ll do that.

What would be the radiator recommendation?
Have my mechanic test it on the van or pull it and take it to a dedicated radiator shop for testing?

If you got another fan I'd probably try that 1st. If your funds are limited then go with your gut. Whenever I go deep enough to do a head gasket, if I have any doubts about the radiator I'll take it into a radiator shop and have it cooked and flow tested/pressure tested. If it needs to be re-cored they let me know and I'll usually just go with whatever they recommend. Of course these are no longer cheap. The last one I had completely re-cored was about a year ago and it ran me almost $1k. That van is my daily driver and runs cool as a cucumber. The temp gauge never leaves the ¼ mark. I chose the high efficiency core and I don't regret spending the $$$. The piece of mind is worth it for me. Tim

Looks like I'm in for a Head Gasket job :cry: Which I'll let the professional mechanic tackle. But I'm on the hunt for parts!

From reading previous threads, with the Valve Grind Kit 04112-73035 being discontinued - is my best bet OEM Head Gasket 11115-73030 and aftermarket kit for the rest? Or are there any other gaskets i should make sure are Toyota?

Mechanic requested new head bolts but parts guy says he's not confident he can get all 10 - any suggestions there?

Hey Tim:

I am changing my head gasket and when I compare the new with the block the holes are different where the water jacket is. Can you take a look at these pics? They use holes in some areas and not triangles.

I made red circles around where there are holes on the gasket and then where they line up on the head. You can see that only 4 triangles are on the gasket compared to 7 on the block. The remaining are just holes.

Do you think this was done intentionally?

What brand gasket is that? I believe the OE Toyota head gaskets to be NLA, but if you can get one of those, that would be my 1st choice. FWIW, I don't know a lot about why the gaskets don't always match, but IMO, I think the casting holes are only approximate and Toyota likely dials things in with the size/location of the holes they put into the head gaskets. I don't have a lot of trust in aftermarket brands, but I totally trust Toyota gaskets to be accurate and of high quality. I just dug out one of my OE Toyota head gaskets and snapped some pics for you to compare:

OE Toyota 4Y head gasket (top)

https://hosting.photobucket.com/imag...Toyota_top.JPG

OE Toyota 4Y head gasket (bottom)

https://hosting.photobucket.com/imag...ota_bottom.JPG



FYI, I also have several other brands of gaskets in my inventory. With the possible exception of the MLS gasket (last one pictured) I probably won't use any of these until my Toyota inventory is used up. I'm posting more pics below for you to compare:

ITM aftermarket 4Y head gasket (top)

https://hosting.photobucket.com/imag...rv/ITM_Top.JPG

ITM aftermarket 4y head gasket (bottom)

https://hosting.photobucket.com/imag...ITM_bottom.JPG

Note: This ITM gasket appears to be of high quality and I would not hesitate to try it when my Toyota gaskets are depleted.

Engine Tech aftermarket 4y head gasket (top)

https://hosting.photobucket.com/imag...e_Tech_top.JPG

Engine Tech aftermarket 4y head gasket (bottom)

https://hosting.photobucket.com/imag...ech_bottom.JPG

Note: This Engine Tech gasket also appears to be of high quality

McCord aftermarket 4y head gasket (top)

https://hosting.photobucket.com/imag...McCord_Top.JPG

McCord aftermarket 4y head gasket (bottom)

https://hosting.photobucket.com/imag...ord_bottom.JPG

Note: This McCord gasket appears to be of questionable quality. I would avoid this brand.

Stainless steel shim type MLS head gasket for 4y forklift (top)

https://hosting.photobucket.com/imag...-0024B_top.JPG

Stainless steel shim type MLS head gasket for 4y forklift (bottom)

https://hosting.photobucket.com/imag...24B_bottom.JPG

Note: MLS gaskets typically last longer and hold up to higher pressures (a good choice for superchargers and turbos) but they need a mirror flat surface on the head and block to seal. These are only recommended if you have the engine out and can take to a machine shop for precision machine work. ALSO, since this gasket is sold for forklifts, it does not have all the coolant holes required for automotive applications. If/when I use this I will compare to one of my Toyota OE gaskets and use it as a guide to punch the holes required. Tim

It is made by Fel-Pro. It is the same one I got the first time. But your pics tell a thousand words. Mine is idenical to the OE Toy. The head did not fail on its own. The hose of death broke just as it is leaving the head. I was on the highway at 3200 rpm and did not catch the temp meter in time. The head got warped and piston 2 and 3 lost compression. Turned out the valves in 2 and 3 were also killed. So I have my newly made head and the same head gasket I had before. So I will proceed today getting her re-assembled.

Great pics Tim. Really tells the story well.

Thank you so much.

One more thing Tim. FYI. The hose of death was the recommended Gates hose. When removed it broke appart in my hands. It was no longer soft but instead hard as a rock. I ordered in some high temp 500deg hose to replace it with. Man am I glad I did you cut out in the back of the firewall so I can get to. Whooooof