Help! White Smoke = Big Bucks?

[norcalsuburban]

I am the original owner of a 1994 6.5TD 4x4 Chevy Suburban with only 173.3K miles on it. Mechanically the truck has seen stress free use and I have experienced zero problems –until now- and I considered all prior service to be routine maintenance (fluid, filter, wiper changes, battery replacement, tires, brake pads etc.) . Just recently, I had the 4-speed AT/OD rebuilt (stopped shifting), I had the brake system overhauled (routine service) , I replaced the tires (normal wear) and so on for about $6K. I’m unable to do the work myself.

Soon after –and all of a sudden- massive amounts of white smoke started spewing out of the exhaust pipe! The engine temperature held at 210 -reached 220 max when stopped at a red light- and then returned to 210 when I started moving again. I continued on for another two miles until I reached home (where the truck sits now). The outside of the engine looks fine. The only other obvious sign of a problem is the low radiator fluid level.

A few phone calls and a quick google search scared the heck out of me. I started to learn all about the cracked block problems (1994-1998) -which I haven’t heard of until now!- and I’m told –worst case- to get prepared to pay $12K plus to replace the engine (gas or diesel)! I was told not to consider a long block because it too could have micro cracks that are not detected with conventional testing methods.

After I talked to my insurance provider I’m not sure if I should throw any more money at it. I am unable to do the work myself and I could easily end up investing $20K in a truck that is worth substantially less.

The questions: First, is it possible for me to diagnose the real problem w/o removing and breaking the engine down (I understand that it is virtually impossible to locate the cracks in the block w/o a complete disassembly) and second, are there straight forward simple steps I could follow to determine if it is a blown head gasket, an injector failure or other problem? Any and all advice would be greatly appreciated!

[rameye]

I'll chime in on the head gasket check as thats what took mine down....

Simple...squeeze the upper radiator hose should be squishy..if not , open the cap and drain out any pressure (cold engine of course) ..replace cap tighten.

Next fire it up.....wait a minute...grab the hose again...if it not just a squishy as before and getting harder to squeeze you most likely got the head gasket disease!!!

Now lets talk about motors...rebuilds and prices...

If its a haed gasket its a pretty big deal to change in the engine compartment ...but its done regularly by members....most likely the head is shot...junk..and I wouldnt reccomend changing just one side..do both. You may find that the blown gasket ate up part of the cylinder deck also....the block may have cracking down below..but you cant see that from above.

Pricing....your probably looking at an easy 3K-4K to do just the heads...the assumes that other things will be replaced along the way...(im in th eNortheast so this may sound pricey).

If you really like the truck...you can buy a brand new/ non-china/ made in the good ole USA long block for about 5500 and have somebody toss it in for a couple thousand.

So your call...how long do you see yourself driving this truck...keeping it?? 5 years???

Then ask yourself is the truck worth 1500 bucks a year to keep??

If you dont need your truck but just like it I say let r go.....worth 1-2K blown gasket.

My .02

[JohnC]

If it's making a lot of white smoke, you have coolant in the combustion chamber(s). The tests above are helpful, but, you first must determine if there is any coolant in one of the combustion chambers now. If so it could create a "hydrolock" and turning the engine over could cause further damage. So, first turn the engine over by hand (this is not easy. You can use a big wrench on the nut on the accessory drive pulley). Turn it over until you have rotated it two full turns. If it gets impossible to turn, you can try turning it backwards, again 2 full turns. Once you get the two full turns, it is safe to start it.

I'm guessing the problem is head gasket(s) as cracked blocks are less common in your year and usually result in rapid loss of coolant into the oil pan (check your oil - if it is milky, do not start the engine...) The good news is head gaskets are *much* less costly to repair.

[norcalsuburban]

Thank You! Now I have somewhere to start. Yes - it was a lot of white smoke....massive amounts of white smoke!! I'll check the oil status first and depending on what I find -and if not milky- I'll add more coolant before I try to turn the engine over two full turns by hand. In addition I'll squeeze the upper radiator hose before and after starting the engine (I hope I get that far!). Also, I hope your right regarding my year model (1994); hopefully it's just a blown head gasket and w/o any further damage as a result of the failure and especially a cracked block etc. I'll report my findings.
Thanks again. I appreciate your input.

[norcalsuburban]

What to do? I found no coolant in the engine; the oil is clean. Head gasket? I topped-off the fluids and I drive the sub to the local mechanic w/o any problems. Initially - he too thought it was the head gasket but after he completed a thorough inspection –w/o dismantling the engine- he is convinced the block is cracked. He said he could give me an absolute verdict when I give him the go ahead. What to do?

I’m still not sure if I should throw any more money at it and I’m not sure anyone would want to buy the truck “as is” so I called the local Pick-n-Pull (a first for me). I learned it doesn’t matter that I just put $6K into critical components etc…….It’s is an old truck and they would only give me a whopping $315.00!?!

I’m unable to do the work myself, I ‘m unable to part-out the truck and I could easily end up investing way more money than the truck is worth. Ha! It appears that I’ve already accomplished that! The question now is - should I give the mechanic the go ahead or should I cut my loses and donate the truck to one of the local charities? After all, the truck is 16 years old. Your thoughts and insight regarding my dilemma is appreciated. What to do?

[john8662]

Don't get caught up in what the truck is worth on paper.

I'd fix it, most likely a head gasket.

Have the mechanic perform a compression test so that when things are taken apart they'll know what the cause is. If the mechanic or shop you're dealing with doesn't have the adapter to check compresson for the 6.5 take it somewhere else that has experience in working on the 6.5.

J

[Robyn]

I agree
The issue is a Blown head gasket on either number 1 or 2 cyl (Front two)

The fire ring errodes over time and the fabric material that holds the gasket together turns to mush in the area mentioned.

The likelyhood is that the gasket failure is not real bad as yet.

Now, DONT try to restart the truck since it has sat. There is every reason to believe that there could be coolant in the cylinder.

Trying to do a restart can result in a Hydro lock and this can break either the starter bolts,starter or the block flanges.

I would have your mechanic yank both heads off and see wassup.

Good bet that a good cleanup, new gaskets and new head bolts and your old girl will run fine again.

As was mentioned, Book value means nothing. If the truck is in good shape, you can drive a lot of $$$$$ out of it.

If the heads are not so good, you can get some pretty darned good Aftermarket ones from Clearwater that are affordable.

About $670 per pair to the door.

Keep us posted

Missy

[Old6.2]

You are going to remove the glow plugs for the compression test anyway so why not spin it over with the starter? You should see wet on the inner fender from the bad cylinder.