3VZE coolant leak into intake?
 

Greetings, all.
Newbie here, but plenty of grease under my fingernails. :)

1991 pickup 3VZE 110K miles or so. AT, AC, 2WD.

I first noticed some engine miss at idle when warm. I know miss is less obvious off idle, (probably even less with a 6) but it definitely seemed to run fine off idle. Also idled fine when cold.

I noticed it was overheating; coolant was low, filled it up, seemed OK; though didn't want to start -just once, sounded like the engine was hitting something that kept it from turning, but then started normally. Didn't think much of it at the time.

Overheating again a couple weeks later, filled it up; ran fine, sat for half an hour or so, wouldn't start -again, sounded like engine was hitting something on the way around. After several tries, started normally.

Runs fine, but after about two miles the temperature starts going up.

I get white smoke, but only at idle and on acceleration. Driving at a steady 40MPH, everything seems perfectly normal.

At this point I figure I have water in the cylinders, or a cylinder. Not sure how fast it's losing coolant because my commute is only three miles, so it's very likely that it has been losing coolant and not overheating only because I haven't driven it far enough to make it overheat.

No drips, no external leaks that I've noticed.

Compression check gives me 180 on all six. Spark plugs all look normal though #3 is a very slightly cleaner than the others.

I don't see any oil in the radiator, and I don't feel -or smell- any exhaust from the radiator cap, don't hear any bubbling. Oil cap has milky sludge. Dipstick looks OK, but about a quart and a half high.

Distributor cap contacts look really bad, rotor not so bad, but I replace cap rotor and plugs while I'm in there. I didn't see any carbon tracking in the cap; but with the good compression check I'm figuring the miss was because of the cap.

Now that I've seen the sludge on the bottom of the oil filler cap and see it overheating after 2-3 miles, I don't want to drive it; so I'm not sure if the new distributor cap has fixed the miss; but obviously that's the least of my worries at this point; except that it might possibly be a clue?


So: My conclusion at this point is that there is a leak from the coolant system into the intake manifold. Water in the cylinder(s) causes the starting problem, until the water manages to leak down past the rings into the crankcase. (or gets pushed there while I'm trying to start it).

I just have the Hanes manual.

I've had this truck for about 35K miles. It hasn't needed any work yet aside from routine maintenance except for a brake slave and new contacts in the starter solenoid; so I'm not very familiar with the engine.

I'm trying to figure out where to look for a leak from the cooling system into the intake manifold... but maybe I should be looking at something else?

Any help greatly appreciated. I did a lot of searches and didn't find anything exactly relevant, but read enough posts to appreciate the level of expertise available on this forum -you be some sharp dudes!

You could have a slight head gasket leak. Head gaskets go on those 3.0s all the time, I've been through 3 of them on mine. Not fun :mad2:. You could try some head gasket/radiator stop leak to add to your radiator. If that were to solve your coolant leak for awhile, then you can probably diagnose it as a faulty head gasket.

If the dipstick shows a quart and a half high, I am betting you have a quart and a half of antifreeze in your crankcase. Plan on doing the head gaskets, and don't drive it until you change the oil and get that water out of there.

I'm doing another head gasket on mine because it overheated when a heater hose blew and I lost a bunch of coolant at once. Now I have had an external leak I tracked to the line between the block and the head...yep, another head gasket! These 3.0's are notorious for them.

I have a 92' PU with the 22re. Single cab 5 speed 4x4.

Basically sounds like what I am currently experiencing besides for a few small differences.

1) I removed the thermostat so the coolant can flow while cold. This allowed me to pop the cap off the radiator and watch the coolant flow while the engine ran at cold temp.

What I see when I do this is a constant sea of small bubbles that bring small wafts of exhaust which escape through the radiator.

2) I do not have a hard time starting my engine. This along with my oil being non-milky and my oil level not going up tells me mine is a much smaller leak than yours.


Besides for these small differences I have pretty much the same issue. The issues being that the head gasket has a leak between the coolant jacket that runs through the engine block and the combustion chamber(s).

In my case this causes coolant to be "sucked" into the cylinder during the intake stroke only to be burned off during the power stroke. When the piston goes up for the Exhaust stroke the exhaust gasses are pushed through the leak in the head gasket into the coolant jacket.

The exhaust is obviously VERY hot and when "pumped" into the coolant system raises the temp of the coolant thus reducing the ability of the coolant to cool the engine.

That is what both our engines are doing only yours is a larger leak allowing more coolant to enter the cylinder and more exhaust to enter the coolant jacket.




LOOK FOR THESE TELL TELL SIGNS!

- Steam being expelled out of the radiator overflow reservoir tube.
- (first remove the thermostat so coolant can flow while the engine is cold) Remove radiator cap and run engine cold. Check for bubbles and exhaust vapors in the radiator.
- Exhaust coming from tailpipe will be white as hell.

I'll save you some time though with testing I can tell you have an Internal Head Gasket failure between your coolant jacket and cylinder. Remove and replace ASAP and for your own sake stop driving it...IF YOU MUST DRIVE CHANGE OIL AND REMOVE THERMOSTAT IMMEDIATELY. This will let your coolant flow the moment your engine is running.

Best of luck.

Not any more, now you have a FSM: :D http://personal.utulsa.edu/~nathan-b...fsm/index.html

Thats basically an online Hanes Manual :think:

Nope those are a scanned in FSM. Here's some more for you too: http://www.ttora.com/forum/showthread.php?t=59089

And I do know what one looks like:

http://i796.photobucket.com/albums/y...t/IMG_0620.jpg

My personal book case:

http://i796.photobucket.com/albums/y...t/IMG_0621.jpg

are those the factory manuals if so can you get them for 1992 and earlier models? if so you should post back. thanks.

Yes, FSM = (factory service manual). The 92 is basically the same as the 93, just use the 93 online. If you keep watch on ebay you might see hard copies of other years but hard copies are pricey from Toyota. There are digital copies available somewhere online to download for a price too.

mt goat have you ever seen a Hanes Manual? There is basically all the same diagrams inside them as you FSMs have, and there are brief discriptions and some step by step maintenance instructions. So, unless your FSMs are highly detailed step-by-step cookbooks, which they do not appear to be, then they are the same.

Yeah I started off with one a a long time ago when I first got my truck. It does use some of the same pics, they probably copy them from the FSM, but the descriptions are very much lacking, some are all mixed up and wrong. I remember one proceedure where they had obviously mixed up the steps with doing something else...it was just a mess. They try to lump too many years and models together in a manual about 1/4 or less the size. In short they suck, so I was giving the guy a better manual to use. Maybe he will appreciate it, even if you don't. :facepalm:

Tsk Tsk, Coastal runner, the Haynes is a sad comparison to the FSM and all the advice here. The online posts here are enormously helpful, please be at least respectful. And good luck on your little head gasket project. I imagine the Haynes manual is full of helpful tips like "be sure to hit the cam gear bolts with the impact wrench, to break the threadlock, BEFORE you take the timing belt off".

I'm sorry, I dont mean to be hard on you. But like when I looked at the exhaust system and the lubrication system- service specifications they were just the same. But now I have found the areas with good detailed descriptions. :drunk::great:

Thank you ! :)
 

Thank you for the links to the FSM. Haynes seem to be the best of the aftermarket manuals (Clymers, anyone? !!) but they are limited, I definitely appreciate the link. My Haynes doesn't seem to have anything useful on this particular issue.

Right after my original posting, I loosened the radiator cap to keep it from building pressure, and all of my problems went away.

I'm figuring the miss was from the distributor cap, and the slightly cleaner #6 was because it was getting washed in gasoline when it was misfiring.

No more smoke or steam out the exhaust, and the oil level has gone down (water evaporated off) and it looks normal -though I know it's got to be contaminated with glycol and I'm going to change it as soon as I get this situation resolved.

Three days of driving (six 3-mile trips) only lost 2 quarts of coolant; no doubt just to losing steam through the loose radiator cap.

I haven't driven it since, and haven't had a chance to do anything with it, but today I'm going to peruse the FSM and see if I can find someplace where the coolant passages interface with the intake.

If I can find something there I'll go after it, but if not, this seems like an ideal candidate for K&W Block Seal. I used that once on a Mazda RX-4 -the car was still on the road several years later.

From what I'm hearing/reading, I'm inclined to agree with the guy who said not to knock K&W as a "temporary" repair since (aside from my own experience with the Mazda) replacing the HG on these engines doesn't seem to be any more permanent.

It would make sense to me that if you had a marginal seal of a gasket and it only leaked during times of high coolant pressure then going to a zero pressure cooling system like you did might temporarily make the problem go away.

I have often thought about what I'd do if I had an old vehicle with a blown head gasket that wasn't worth repairing (not saying you are there). I think I would consider some type of fix a leak stuff in that situation. If I did it I'd probably close off the heater hose flow to keep that crap out of the heater core, and expect small passages in the whole cooling system to be partly blocked. I'd expect to have to replace the radiator soon after.