97 v6 head gasket failure? diagnosis and opinions wanted.

[flynbya2]

I am thinking this might be what has happened.My son has been driving the 97 forerunner and the other day he called me and said it was blowing white smoke,so he drove it back home and parked it(1/2 mile or so). He said it was missing a little too.

So when I went to check it out,coolant resevoir was empty,but radiator still had fluid in it.Oil is golden and not frothy at all.(this part throws me...)My son stated it never overheated while he was driving it,fwiw.

I tried to start the engine,but it acts like a dead battery,even though it's not.It's almost like it's frozen. It tries to turn then all dash lights go dim to dead,until I try again.Don't want to fry the starter.A neighbor stated a cylinder could be full of coolant causing it to act similar to frozen.

At this point,I need advice....
This engine has 135k on it.What steps should I take to diagnose if it is a head gasket and which one? What other potential problems might I run into that would add to the repair cost? Is this common for these v-6's,or unusual?
I have found a used engine for 1,250 with 67k miles on it. Do you think I would be better off just swapping that one out? It would probably need timing belt,water pump,etc. I can see it running about $2k if I go this route,but it is an option.

What are the down sides of just replacing the head gasket,if that is what it is?
I am concerned about longevity,with coolant in the cylinder(s) and all,even though the oil looks pristine.

What sort of advise would anyone with lots of knowledge on these engines give me?

TIA. First post BTW!

[HATEnFATE]

the answer is really going to depend on what you think the cvalue of the runner is. Do you feel it is worth dropping an engine in?

Personally, for the price you've found a used engine for, i would go that route. Much less hassle and headache(usually) by dropping an engine. make sure you find someone you trust to do the work if you aren't doing it yourself.

for diag.....did you check the oil on the stick or did you drain it and check? If you haven't drained it, start there. See if there is anything sitting in it like metal particles and such. If there is coolant in a cylinder, it would likely drain out after sitting for an extended period of time(overnight or just a little longer) and end up in the oil pan anyway.

What did the coolant look like that was still in the radiator? was it cloudy or oily?

Sounds like if it is a headgasket, it's a small break between the water passages and the cylinder and doesn't involve the oil but it will once the coolant drains out of the cylinder thats full, if that is what's locking it up.

let me know what you find.

You can pull spark plugs and maybe dip a screwdriver into the cylinder and see if one comes out with coolant on it.

[kevsgonefishing]

I had the same problem but mine blew BIG TIME!!!! It started out just doing the heads but I found out it also needed a valve job. The cost to do that and Adj the valves(cuz I didnt know but I turned the heads upside down and dropped all the cups out and didnt know that it where the valve adj is) So to completely redo the heads was almost $1K. There is a company up here in Nor Cal called Attarco, I got a RB from them for $1550.00 plus a $500.00 core(which I got back) I think that was the best way to go for me. I have a 97 4Runner 3.4 it had around 280K when the gasket let go. R/Ring the engine isnt as bad as it looks, buy a Chiltons Manual and fallow it step by step and take lots of pics and label all your wires and hoses, it actually wasnt that bad now when I look back on it, I just finished mine a couple weeks ago.......good luck. This is just MHO.
Kev

[toytruck89]

the 3.4 is a pretty resilient motor. having the heads redone won't be bad at all if you find a reputable machine shop. (I could call and find one there for you, I have a friend that owns a shop down there.) if you never overheated it, it's likely that it won't need valve work, just resurfacing on the heads.

as for checking the head gasket in the first place, you can get a chemical head gasket checker at the parts store (Kragen, Autozone, etc). It's the only way to know 100% if the head gasket is blown.

if the 4runner is just blowing smoke, you might have cracked an intake manifold gasket or jacket and be lettting water into the cylinder (hence the frozen-ness)


IF IT WERE MY TRUCK, I would pull the spark plugs and see if it cranks over. and I would check each spark plug as I pulled it for evidence of water. If you buy a chilton's manual (or just look at one in the auto store--Kragen stocks them) it will show you pictures of how spark plugs should look on the back page of the manual.

let us know what you find

[kevsgonefishing]

Well for me a new engine was the best option. My valves had about 30% leakage, so they were in need of a valve job, hence the high $$$ to rebuild the heads. My gasket let go at the farthest rear cyl on the left side(facing the engine). That one cyl was full of water and mine wouldnt crank either. I did get mine hot but not bad enough to lock the engine up. Due to the mileage on mine and the % of leakage from my valves a new engine was my best option.

I would pull the plugs and look for any wet ones, maybe even stick a.......pipe cleaner into each cyl to look for coolent. Whatever you decide good luck to you. Keep us informed.

[flynbya2]

Originally Posted by toytruck89

as for checking the head gasket in the first place, you can get a chemical head gasket checker at the parts store (Kragen, Autozone, etc). It's the only way to know 100% if the head gasket is blown.

if the 4runner is just blowing smoke, you might have cracked an intake manifold gasket or jacket and be lettting water into the cylinder (hence the frozen-ness)


IF IT WERE MY TRUCK, I would pull the spark plugs and see if it cranks over. and I would check each spark plug as I pulled it for evidence of water. If you buy a chilton's manual (or just look at one in the auto store--Kragen stocks them) it will show you pictures of how spark plugs should look on the back page of the manual.

let us know what you find

Well I would like to thank each of you for all for your input.I quoted this because there were 2 interesting things here I did not know.
First,I did not know about this chemical headgasket check you speak of.Not sure how it works,but interesting anyway.
Secondly,I never thought about it being an intake gasket.

Honestly,I have been so upset over this,I haven't looked at it again yet.Didn't want to see it for a while I guess.I had pretty much accepted the fact it's head gasket and have been trying to decide which way to go forward.

I called a friend/mechanic and asked for a quote for HG repair,when he said his shop didn't really want to get into it,and gave me a qualified referral.Turns out I have used this guy for my f350 diesel before and he was pretty good as I remember. A short phone call later and his phone quote was +/-$1,800 total for machine work on both heads,parts, labor and incedentals. Said he would only do both heads.

So now going with this used,unopened 66k engine is sounding much more appealing. It should be a little over 2k if I have them do the timing belt at the same time.

But,after reading the above I am left wondering if it's just an intake manifold gasket issue. Or will I still have to do the heads either way since there is,or was,fluid in at least one cylinder.(assuming there is)

Guess it's time I look a little closer.

[chuckoff]

A compression test will reveal a blown head gasket/warped head. If that is the case, it is best to remove both heads and take to a qualified machinist. The heads need to be repaired and the valve job done. You can't half ass this repair and expect good results.
Doing that repair as well as fixing whatever caused it to loose coolant/ overheat in the first place should cost 1500 to 2000. Failed intake gaskets on this engine will not cause coolant to enter combustion chamber.