Head gasket replacement problems

[worcester4x4]

dang, this guy will have to wait the whole time they take it apart...?
that may get expensive no?

$400 including the report.

What else can I do? I want him there while the head actually comes off so that he can see the unadulterated condition of the gasket & head,

I do remember seeing several reports of compression numbers where all 6 were within 1 or 2 psi. Could this be a wider variation than usual?

The spec is 175 psi +/- 30psi difference between pots so they're all over spec but within the differential tolerance. I'm not sure quite what it means but I would have thought that any leak between the cylinders and the coolant circuit would show up as low compression? No?

Pete

 

[concretejungle]

i think the key to the compression numbers is that they should be within a few (1-3) psi all across.

 

[worcester4x4]

i think the key to the compression numbers is that they should be within a few (1-3) psi all across.

For sure the closer the compression between cylinders the better but they're all high and 5 & 6 are haigher still.

Interestingly.... or not... between 5 and 6 is where the HG blew and that's where it's giving high compression now. Coolant in the cylinders raising the compression?

Should I get a leakdown test done as well? Will that give more useful info?

Pete

 

[worcester4x4]

I'm beginning to think I should cut my losses and get the engine fully reconditioned.

I'm just going round in circles right now!

Pete

 

[Tools R Us]

His statement of; "we've put it all back together but as soon as we start it the coolant is ejected from the open rad cap." is what nails it for me. Most block/head cracks start out as very small leaks, when the motor is cold they don't leak much and as the motor warms up they leak more, many times hard to imposable to diagnose on a cold motor.

For it to eject coolant from a cold motor I would bet it's a significant leak, more than likely gasket related. For it to be a crack and work that way it has to be in the combustion area, the top .5" or so of the cylinder or dome or fire ring sealing area of the head. If it's a crack large enough to cause coolant to be ejected from a cold motor, you probably wont need dye, it would be obvious.

 

[archie]

That's a very good plan.

Unfortunately I don't know anyone local with any engine rebuild experience

Pete

post your location, maybe you'll get volunteer with experience in HG replacement

 

[IdahoDoug]

Kevin,

That's a really good observation and I wholeheartedly agree. This will be a gasket issue. Very, very good point and nice armchair diagnosis.

Tell the observer to show up only when the valve cover comes off so he'll watch them loosen the head bolts. Remove cams, then remove head bolts, then remove head is the sequence after the cover comes off.

Don't lose heart with this, but do have an observer there. Someone there on the shop's staff knows what happened (likely bumped the head against the gasket - doesn't take much) and they'll want to cover it up. The owner may have no clue it happened. Watch for someone to suddenly quit during the teardown.

DougM

 

[seandaniels]

1988 4Runner Head Gasket Start Problem

just bought a 1988 4Runner 140k miles,V6 with blown drivers side head gasket. It started when I bought it alot of white smoke. Next day I cant seem to restart it. It turns over fine and starts to fire but wont keep running. Ive taken the spark plugs out and cleaned them and turned over engine to blow out water. There is no water in oil. I havn't decided whether to do head gasket myself or not yet. Looking for advice. Thanks

 

[worcester4x4]

The news is not so good and I'm back, cap-in-hand for more help and advice.

The shop took the head off today in the prescence of the consultant engineer and me.

The bolts were not marked with paint; when I asked about this the shop manager said there was no need to do this and it wasn't in the FSM.

However, leaving that aside:

The head looks absolutely perfect, no sign of any cracks, no combustion gas escape marking, no coolant in any of the pots. The face of the head is absolutely flat.

No sign of any visible cracks in the top of the block.

No sign of any marks on the gasket, not even the faintest scratch on the fire rings.

In fact there was no sign of anything wrong at all!

The engineer has no ideas, he could see nothing wrong. He's going to write me a report but he's already said it won't say anything untoward.

So what gives? What do I look for now?

Does anyone have a photo of a genuine head gasket that they could email me or post up on here? The best resolution image possible please. The only unknown left from my point of view is "is this the correct gasket" and I can only tell if I compare the old one with a known correct one.

Could someone send me a pic please?

Thanks again in advance.

Pete
​

 

[IdahoDoug]

I'd suspect the head first for any cracking issues, so have that rechecked by the machine shop that worked on it before turning to the block.

You say no water in the cylinders. Did they do the coolant pressure test with the engine stopped that would have put the water in there? I suggested it but did not hear. If not, that was a major loss of information that could have pointed to something. That's a bummer because wherever the leak is, it would have had coolant flowing back into it (vs combustion gases you saw which were going the other way through this leak) and been easy to identify. That was the whole point.

Saying the paint is not part of the FSM. Yes, it is - mark the head bolts for the last two turns.

If I were you: Send the head to be pressure tested by the shop that previously worked on it and pressure tested it. Identify the gasket's origin - Toyota part or some off brand. You should provide pictures for posting here. THey should also know where it came from.

DougM

 

[worcester4x4]

Sorry, I should have said.... the shop said they reverse pressurised the cooling system at 15 psi for 2 hours. There was no trace of any coolant in the bores.

OK, I'll get the head pressure tested again.

I should also have said that my engineer sniffed the rad cap and said that the engine had definitely overheated - he could tell by the smell.

As soon as I've photographed the gasket I'll post it.

Pete

 

[Beowulf]

just bought a 1988 4Runner 140k miles,V6 with blown drivers side head gasket.

Wrong forum Sean. This section is for 80-Series Land Cruisers (1991-1997 model years.) There is another section here on 'Mud for mini-trucks and 4Runners. You will want to introduce yourself and start a new thread and give as much information as possible.

-B-

 

[corsair23]

Pete,

Any news? I hate not knowing how the story ends

 

[donburks]

Head gasket problems

Have you looked at the top of the block? When my head gasket blew (94 1FZ) there were "worm" like channels etched in the block where the gasket failed and I had to have the top of the blocked shaved to get it smooth and flat again.

Don