Bought A 94 LT5 With Known Problem

[billybaloneey]

I bought a 94 LT5 engine with a known problem...an internal coolant leak. The engine has 149K on it, and it came out of VIN #424. It was posted on a major Internet auction site earlier this week. I was fortunate enough to be with driving distance...35 miles...I asked the seller if I could come and take a look at it and he said OK. The auction description said water was observed coming out from around the throttle body, so he put a new one on...that did not fix the problem so he put a new plenum on...that did not fix the problem...he reported coolant/steam coming out of both exhausts. At that point he shut it down and pulled the engine and replaced it with a crate motor he found...he is a GM part employee...so I guess he had some contacts. I saw the car...it was red...and there was a brand new LT5 engine...or one very, very, very clean LT5 in it.

Anyway, in addition to the engine being offered on the auction site, he told me it was listed locally for sale. After two offers he accepted, and I got it for significantly less that the auction asking price.

I picked it up today and started investigating. There is coolant in the oil pan and in the oil filter, so it appears coolant is throughout the engine. I could turn the crank without to much effort so the engine is not seized.

Any suggestions from you engine experts out there? Are typical internal coolant leaks on the LT5 due to gasket failures, block cracks, head cracks, etc? If there is a crack are they typically easy to spot? Are cracks prone to certain areas? Any suggested plan of attacks to locate the cause of the coolant leak?

For the price I got it at, even if it's cost prohibitive to fix or turn it into a stroker, I have a great source of parts...as mentioned there is a new plenum and throttle body on it...he gave the the old ones also. As can be seen from the pictures the engine is virtually complete...including a bell housing, clutch and flywheel. The only thing I've found missing so far is the dipstick and tube. He even included the engine lifting mounts.


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/LT5EngineBuy1-1.jpg

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/LT5EngineBuy3.jpg

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/LT5EngineBuy2.jpg

[MikeG]

Clint, I just had new head gaskets put on my 91 (68+K) - white "fog" coming out both exhausts. The only way I know of to tell the condition would be to start with pulling the heads. Mine was on the right bank - #8. Left bank was OK. From some of the threads I've read, the back 2 cylinders are the one most prone to fail. Most of the info I got from the forum was under "head gasket", try that search and I know some other guys will be posting here soon.
It will be nice to have a "spare" motor handy - if there isn't too much wrong with the lower end. Hope it turns out to just be a minor problem.

[phrogs]

really im thinking head gasket.

Here the deal tear it down and see what you can find, you have the tools know and anything you need to put it back together we can help with that!..


Its really easy to do and it fun to see the inside of the engine at least it is for me I love this stuff!

[billybaloneey]

I don't have much spare time at the moment to begin investigating the internal reasons for coolant mixed in with the oil, but when I do, it looks like I'll have a big clean-up job ahead of me. Can anyone recommend a cleaner/solvent to get rid of the mix of coolant/oil that is sure to be everywhere? Or is the best approach to just take the major components and have them hot tanked?

[phrogs]

I have just used degreaser and cleaned it like that oh and lots of brake cleaner.

I don't have a hot tank and you wont hurt the plenum and cam covers powder coat if you get crazy cause its already done!

you could take it all apart and pay someone to hot tank it I guess I wouldn't. just a old tooth brush and some brake cleaner thats me:thumbsup:

[Jagdpanzer]

You should tear this engine down as soon as you can. By the looks of it the biggest concern is corrosion on the bearing journals, timing chains, cam lobes, lifters, valve stems, and gear teeth caused by the coolant that found its way to the lube oil side. With this many miles if the previous owner(s) did not properly maintain the coolant you may find some pitting on the cylinder head deck in the cylinder liner sealing area and where the liners insert into the block. Then take it to a local shop and hot tank it.

[billybaloneey]

I'm putting together my shopping list and would like some suggested sources (reasonably priced) for:

1) piston rings (standard/stock size)
2) crankshaft bearings (standard/stock size)

Will an engine with 149K typically need a lot of the timing chain parts, (chains, guides, strips, inserts, etc), replaced?

I have located Loctite 242 (Blue) and Loctite 262 (Red) at Autozone, but can't find Loctite 565 or Loctite 620...both of which are called for in the service manual. Can anyone recommend a suitable substitute? Also is there a suitable substitute for Permabond A136...used for sealing the case and heads?

I just placed an order for all of my gasket and seal needs, from Jerry's Gaskets...a great guy to do business with, not to mention great prices.

Thanks,

[Kb7tif]

Well my 92 engine was pulled for a complete gasket set, they found wear on the main bearings, those were replaced at 110k.

[LGAFF]

You might be able to send your bearings to Calico and have them recoated:http://www.calicocoatings.com/faqs/

[billybaloneey]

Progress Pictures Part 1:

Accessories awaiting removal -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/AccessoriesAwaitingRemoval.jpg


Accessories removed -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/AccessoriesRemoved.jpg


Coolant tube, internal corrosion -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/CoolantTube-InternalCorrosion.jpg


Oil pan draining oil & coolant mix -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/OilPan-DrainingOilAndWaterMix.jpg


Damper removal -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/DamperRemoval.jpg


Front engine cover, damper and water pump removed -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/FrontCoverDamperAndWaterPumpRemoved.jpg

[billybaloneey]

Progress Pictures Part 2:

Head exposed & lifters removed -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/RightSideHeadLiftersRemoved.jpg


Breaking loose head bolts -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/RemovingHeadBolts1.jpg


Head Bolts awaiting removal -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/HeadBoltsBackedOut-OilAndWaterBrown.jpg


Cams, lifters and head bolts removed -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/CamsLiftersAndHeadBoltsRemoved.jpg


A look behind the front engine cover -

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/ChainDrive.jpg


I can't figure out how to remove the heads after the 10 head bolts have been removed from each side. I have tried tapping the head with a rubber mallet, I tried gentle prying with a screw driver. I have gone through the service manual and I can't find any reference to any special head removal procedure.

Anyone out there have any tips on getting the heads removed? I'm suspecting there are dowel pins (guide pins), does anyone know where they are located on the case/head?

[Jeffvette]

There are two dowel pins. Use a bigger rubber mallet.


Also just remove all your wiring harness and fuel rails. It'll just get int the way.

[phrogs]

There are two dowel pins. Use a bigger rubber mallet.


Also just remove all your wiring harness and fuel rails. It'll just get int the way.



:iamwithst

Don't tap it with the rubber mallet wack it with the mallet kinda under and up just like jeff said there are dowel pins stick up a little over a 1/4 of an inch over the base of the block.

You'll see give it a good wack don't be afraid you wont hurt it.




Hard to see in this picture but I love it


http://i150.photobucket.com/albums/s103/zr1salvage/DRM/lappypics14667.jpg

[4DSZR1]

Great pictures, documenting your tear-down. I enjoy and appreciate you taking the time to post them.

I was wondering if anyone knows what the "1040" written on the front of the block means???

Rick

[Polo-1]

1040's were know to leak water. These motors were built right after break time, on the line.:wink:

[tf95ZR1]

I was wondering if anyone knows what the "1040" written on the front of the block means???

Rick

Tomorrow is Tax day. Tax Form 1040. Reminding you to pay up.

[Pete]

The fixed chain guides are bolted to the heads,one on each side.
There is 1 plug in front of each head (13mm) take those out and you will see the 10mm screws.

When your ready to remove the heads make sure you don't bumb the plastic guides while removing the heads you can break them.

Don't ask me how i know.

Pete

[billybaloneey]

Engine damage update #1

I managed to get the heads off today and got a first hand look at the damage. Before I got the heads off, based on the #5 spark plug and #5 exhaust port, I thought the problem was going to be on #5, and sure enough thats where the damage was.

#5 cylinder liner and piston damage:

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5-Brokenlinerandpistonch-3.jpg


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5-Brokenlinerandpistonch-2.jpg


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5-Brokenlinerandpistonch-1.jpg


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5-Brokenlinerandpistonchip-.jpg


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder3-5-7.jpg


http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5-damage-1.jpg

[Kb7tif]

Damage to head?

[billybaloneey]

Engine damage update #2:

#5 combustion chamber and head gasket damage -

The head gasket remains in place just as it appeared when the head was lifted off of the block.

http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5combustionchamberdamage-1.jpg


All four corners of the combustion chamber show some damagehttp://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5combustionchamberdamageand.jpg

The gasket on top is from the other side of the engine is is used for comparison...close inspection shows the beginning of gasket failure (cracks and rust)
http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Cylinder5headgasketrotting-1.jpg

#5 is on the right, #7 is on the left
http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Leftheadcylinder7-5lefttoright.jpg


The area around #5 got so hot it melted several of the plastic secondary assembly connectors:
http://i128.photobucket.com/albums/p194/billybaloneey/LT5%20Engine/Meltedsecondaryassembly-1.jpg

Engine experts - I have several questions:

1) are stock pistons and cylinder liners inter-changeable from '91 to '94?
2) the combustion chamber damage...can it be welded/repaired?
3) there is no visible valve damage...but to be on the safe side I might change them out...are stock valves (intake and exhaust) interchangeable from '91 to '94?

[Kb7tif]

^^

[billybaloneey]

I've not made much more progress on tearing down the engine other than my last post with pictures. I got my hands on a complete set of used '91 piston assemblies (pistons, rods, rings, pins, etc) and liners, which I planned to use to replace any damaged parts. Marc H. dealt me a set back when he told me of a piston & rod weight difference between the '91 and '94. The liners I have are usable. I will end up having to buy another piston(s) and rod(s).

My initial engine dis-assembly took place while the engine was still sitting on the shipping crate. I have since put the remainder of the engine on an engine stand for easier access to the bottom end. I have yet to dis-assemble the heads (valves, springs, etc). After a complete tear down and inspection, then replacing what needs to be replaced, cleaning every part to like new condition is my next goal...there are lots of inspirational clean engine pictures on the forum.

This engine is a spare, so I'm in no hurry. Quality time to spend working on the engine is just not available to me at this time.

One of our fellow forum members, (rhipsher), has my plenum and injector housings which are under going porting, and Jerry's Gaskets has provided me with all my gasket needs.

[todesengel]

yeah, he shut that thing right off after he seen it leaking coolant. With it getting as hot as it did I would check every mating surface on that block, and heads.

Milling will not bring the heads back true. You will wind up with a flat surface for the gasket, but could wind up with your cams binding badly in the heads. I would check them for tolerance, and if warped AND you want to save it/them have them heated and straightened, THEN milled. When you can buy spare heads for 500 apiece, I think that would be the route I would go.

[Jagdpanzer]

I have a full set of rods, pistons & liners removed from the 94 LT5 for my 402 stroker project. What do you need?