jrs944 head gasket project

[jrs944]

I found this 1994 v6 on CL last week and had to get it. Only 162,000 miles and good shape. PO said it had a warped head and, or blown head gasket. It does have a blown he'd gasket on No. 6 cylinder and will let the machine shop decide if the heads are warped.

Here it is after we pulled it home.


Here is the gasket on cylinder no. 6.

Engine on its way out.

Engine on the stand.

I will send pics as the rebuild goes on. I am hoping that the bottom end is OK. I hope to replace the seals, gaskets, oil and water pump, timing belt and knock sensor.

 

[92-SR5]

You have any plans to do headers or something to avoid cooking the head again?

 

[jrs944]

Not going to be a daily driver so I doubt it. What does a set of headers cost?

 

[Cmwise]

The headers I found were about 600 to 700 but from I've heard they make a night and day difference. I am also in the process of redoin my head gasket. Will be following so keep the pics comin

 

[jrs944]

I'm not looking to sink a lot of money into this truck so headers are not on my list. Since I have the motor out and on a stand, I am going to check the main and rod bearings with plastigage. I will take pics and get them on here soon.

 

[Cmwise]

Now will u be studdingn the heads down?

 

[jrs944]

I'm not sure what you mean by studding the heads down.

 

[jrs944]

Here are pictures of my plastigage on the main and rod bearings. All measurements came in at .038 mm which look to be within tolerance. The crank looked good, but the rod bearings did not. I didn't really want to take the entire engine to the machine shop. It looks like I am headed for a master rebuild kit. Please look at the pics and give me your opinion on where to take it from here.

 

[Jayzero911]

I had and have driven on much worse. Bought a 97 Neon few years ago and it had a loud knock. Found out the rod bearings on #2 where all but gone (vary thin and missing about 15% of the ends). I ran down to NAPA and got standard replacement bearings (I was young and didn't know to get oversized lol)and put the thing back together. Ran great and strong tell it was impounded but had a little ticking sound. Had I gotten the oversized bearings it would have probably been fine. 2 weeks later my friends Eclipse backfired on him or something like that and he got the knock I had (420a same engines), He installed the standard bearings too and the car is still his DD. Only difference he has now is he knows when his oil is running low cuz the tick starts to come back.

Too me your crank looks fine and I would just replace the bearings, they don't look that worn too me(doubt you had a rod bearing tick before right).

 

[RiFF RaFF]

Doesn't look too bad, but since you have it torn down that far - you may want to just bite the bullet, and do it up right. Complete rebuild and you're engine will go another 100K plus miles.

JMO - that's what I would do since I plan on keeping my 4Runner for a very long time.

:usa2:

 

[jrs944]

Doesn't look too bad, but since you have it torn down that far - you may want to just bite the bullet, and do it up right. Complete rebuild and you're engine will go another 100K plus miles.

JMO - that's what I would do since I plan on keeping my 4Runner for a very long time.

:usa2:

I agree with the complete rebuild. I need to find a machine shop to deck the heads and check the cylinder bore. After that, I can order the parts. Do I need to get the crankshaft looked at?
This is my first engine rebuild. Wish me luck.........

 

[RiFF RaFF]

I agree with the complete rebuild. I need to find a machine shop to deck the heads and check the cylinder bore. After that, I can order the parts. Do I need to get the crankshaft looked at?
This is my first engine rebuild. Wish me luck.........

If the machine shop does magnafluxing might be good to have the heads/block/cams and crank done to insure there are no cracks.

:decision:

 

[jrs944]

Too me your crank looks fine and I would just replace the bearings, they don't look that worn too me(doubt you had a rod bearing tick before right).

I bought this without starting it because the PO had the oil dropped. He dropped the oil because he was sure it blew a head gasket. My son and I towed it home, put oil in it and water in the radiator, fired it up and drove it around the block. It was running rough and blowing water vapor out the exhaust. Didn't really pick up on a bearing tick at that time since I didn't want to run it very long.

 

[jrs944]

I took both heads to the machine shop today. This is what they quoted me. Decking the heads = $31 each head, pressure testing = $31 each head. Not too bad if that is what they bill me for.

I had a little time so I started cleaning the engine bay.

 

[airdreams1]

Good luck on the rebuild.

Just bought a 89 w/3.o that has a blown head gasket as well... (& a seriously leaking water pump) it has over 300K miles on it. & will barley run.... Cant afford a short block, so Im going to have to rebuild it. Going to need some luck on mine as well...

 

[jrs944]

Good luck on the rebuild.

Just bought a 89 w/3.o that has a blown head gasket as well... (& a seriously leaking water pump) it has over 300K miles on it. & will barley run.... Cant afford a short block, so Im going to have to rebuild it. Going to need some luck on mine as well...

How much of a rebuild are you planning to do? If yours is like mine, the block will be covered in grime from years of leaking oil. If you don't want it dripping oil in your driveway when you are done, I would suggest pulling the motor, cleaning the engine and replacing all of the seals and gaskets. I wish I would have pulled mine before trying to work on the head gaskets with the motor in the truck. After I got the drivers side head off I could see that I had to pull the motor. Good luck on your rebuild.........

 

[jrs944]

Going to pick the heads up tomorrow. Both were decked and pressure tested fine. They also did a vacuum test and said one of the exhaust valves showed bad. I told them that I would check the valves since they wanted an additional $300 to do a valve job plus parts. What do you guys think would be the issue with the exhaust valve? A bad spring???? Any input appreciated. I will know more when I get them home.

 

[Jayzero911]

Bad valve normally means the stem is too warn, or to much build up, or even just warn to where it doesn't seat in the chamber completely but that would fail a compression test. Just get the heads back and inspect it yourself. Only 2 tools you need to do a valve job. Valve Spring Clamp, and a Valve Seat Cutter..... looking at $75 for some new tools that you mite or mite not use again. Then the cost of parts. You would be able to do a complete valve job for far less, and maybe you know a few people needing valve jobs. They are really simple to do and I don't see why more people don't do them themselves.

 

[jrs944]

I finally had time to tear the engine all the way down yesterday. I found that the bock had a low spot right where the head gasket failed. Going to take the block to a machine shop to get decked and bored if needed. Glad I noticed the depression in the block. I don't mind wrenching on it, but I'm in no hurry to do it again.

 

[Bumper2Bumper Auto]

First, I would recommend getting the crank at least inspected and the journals polished. When I did mine it was only like $60. It will finish as good as new, and will last much longer.

Second, be careful how much they deck the heads AND the block total. Excessive combined decking can cause the timing to be off a small amount. What happens is that with both the heads and block decked, the camshafts are a small amount closer to the block. While most cases it is not an issue, too much head and block decking can allow the distance between the left and right cylinder heads to be enough where the timing belt will fit, but there will be s small difference in where the camshaft gear timing mark lines up with the back cover plate. This will result in a small, but noticeable amount of power loss.