1991 Landcrusier Overheats- After Head gasket replacement.

[Alaskan LC]

I replaced my daughters 1991 Landcruiser's head gasket this winter because the rig suddenly began running hot. I found a coolant trace on the old head gasket so I felt I was on to the culprit. I had the head reworked by a reputable machine shop and also had them pressure test and flux it for cracks.

Put it back to gether and still overheating.

I then took it to the local Toyota dealer here in Anchorage. They told me that the ports were blocked and that there was no flow getting through the head. Their theory was that I had put the head gasket on upside down and thereby blocked the ports. I had taken hundreds of pictures of the process but as luck would have it, I did not have a good one showing the gasket when placed on the head.

Reeling in disbelief and feeling fairly inadequate, I asked them to take it back down and fix it. That has happened and they called me yesterday saying that I had the gasket on correctly. They replaced it and put it back together and it still is overheating! They now say it is the head that is bad. They want to take it back down and I asked them to wait until monday so I could think about other possibilities.

I remember in the back of my mind (I may have dreamed it)reading a post on this site concerning air locking in the 80 series coolant system and that one had to jack the front or the rear end up as high as possible to break it. Does any one know what I am thinking of or is it wishful thinking on my part. I have tried to locate the thread by searching but cannot find it.

I love the rig, have owned it since 2000 (second owner) and gave it to my 16 year old daughter because it eats snow for breakfast and it is the same age as she is.

Any ideas or help would be appreciated.

 

[inkpot]

Howdy! I would have tried the easy fixes first. Have the radiator rodded/boiled out. Replace the water pump. I have seen pumps where the fins are completely gone, thus, no water flow. And, of course, the first and foremost is service/replace the thermostadt. John

 

[jjcobm]

I remember in the back of my mind (I may have dreamed it)reading a post on this site concerning air locking in the 80 series coolant system and that one had to jack the front or the rear end up as high as possible to break it. Does any one know what I am thinking of or is it wishful thinking on my part. I have tried to locate the thread by searching but cannot find it.

I do remember what you are talking about. Forgot who it was but they jacked it up, left it like that over night, and the next day the air pockets had came out of it and it ran fine. Replace the t-stat (the OEM one has a small bleeder valve for air) and flush the cooling system while you are at it, water pump would also be a probability and should of gotten replaced with that. If you just got the head repaired, I would think they would of seen a clogged passage on it.

 

[D'Animal]

Plugged Radiator is my guess.

 

[alkaline747trio]

Make sure your radiator is flowing well inside and out...clean all mud out of the fins and get the radiator replaced/rodded/boiled.

Make sure all hoses are good.

Do a system backflush with a flushing solvent.

Check thermostat....take it out, if it solves the issue you need a new thermo.

Make sure all heater hoses are in the correct place.

Last option, get a new head....do the gasket again, might as well go .030-.045 off the head, pocket port it, desmog it, then richen things up via the AFM and/or wideband O2s. Removing the EGR and the Cats will drastically improve engine and engine bay temps...plus a good seat of the pants boost in power.
--possible problem = having to run premium because of the increase in air (not being replaced by EGR and PCV gases) and compression.

 

[jonheld]

I replaced my daughters 1991 Landcruiser's head gasket this winter because the rig suddenly began running hot.

Still on the original fan clutch?????

 

[elhombre]

The stealership now says the head is bad....I would like to know what they think is wrong with it. Please tell me if I am wrong but the main two ways a head goes bad is if it is warped or it has a crack in it. With warpage or cracks in the right spots, you should have coolant leaking out of the coolant jacket into places it does not belong. The coolant has to go somewhere and should show up in the exhaust or engine oil. You had it checked for cracks and warpage when it was rebuilt. Ask them what they think is the problem now.

I second checking out the water pump and radiator, but start simple and remove the thermostat first. Jack up the front end so the top of the radiator is higher than the engine. Fill the sytem up slowly so the air has a chance to move out of the block. Squeeze the radiator hoses a bunch to help move coolant around. If you did the head gasket yourself, you are smart enough to figure this out yourself. My guess is that those monkeys at the stealership are completely lost.

 

[e9999]

are they maybe saying that the coolant flow through the head is impaired (as in passages blocked)?

 

[Alaskan LC]

are they maybe saying that the coolant flow through the head is impaired (as in passages blocked)?

Correct. That was the original diagnosis by the dealership. They said that it is possible to place the head gasket on upside down which would cover some of the flow passages. They reached that conclusion because they couldn't get fluid to flow through the head. Proved to be incorrect on the second teardown.

 

[SnapsEighty]

I hope they're not charging you every time they take the top half apart?? Has a stop leak ever been added into the system since you owned it? I've seen this once and it eventually clogged the radiator. When does it overheat while at speeds or at idle or both? If its at speed I'd look into the radiator first being possibly clogged. Good luck. Hope you find it soon.

 

[Alaskan LC]

Thanks for comments!

All good points and items that will be checked.

In my defense, I entered the gasket replacement after taking this rig to a mechanic that has been doing my work all along. His diagnosis was that the head gasket was blown and advised me to trade it for a newer car. He did not want to do the repair because he said it was too time consuming for his shop....my first mistake! I took it on because I had rebuilt some Chevy 350's back in the day with my father.

I plan to start over, checking the simple things and working back towards the head. I will post how it turns out. A costly but learning experience!

By the way, the dealership did say that it is possible to put the gasket on upside down thereby blocking some of the main passages. I did not believe that I could have done that but had a weak moment of selfdoubt that ended up costing me. Was vindicated (but charged 50%) by the second teardown.

 

[inkpot]

are they maybe saying that the coolant flow through the head is impaired (as in passages blocked)?

Howdy! First, let me clarify that I am no engine expert, but I have a more than a few apart over the years. I have seen both heads and blocks with internal blockage. It was, for me, always corrosion/buildup that was indicative of other problems. USUALLY, the smallest passage way in a head are right at the mating surface such as where it meets the block or manifold. If you have the head off, then run some safety wire into all the passage ways. If you don't knock out some turds, then it is pretty likely that they are clear. The holes in the top of the radiator core are the smallest in the cooling system. If there is much trash in the system, it will trap some/most of it there.

As already suggested, I would start with the fan clutch replacement, unless you know it is pretty fresh. It is the easiest to get to. If no better, then look at flushing and rodding the radiator. If no better, next replace the water pump. If no better, then go back into the engine. It's just hard to imagine a significant blockage in the water jacket that cannot be located/seen. John

 

[Alaskan LC]

It doesn't seem to matter if at speed or idle. Heats up quicker at speed. I have never used any stop leak on it in the 7 years I have owned it. I can't say for the prior owner.