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View Full Version : Opinions on what blew?? (Long)


whatnot
08-06-2003, 23:24
During the winter my 93 with the 6.2L Banks turbo got sick.
When it happened, I was driving along at a good speed and noticed I needed a lot more pedal to keep up the speed and smoke was coming from the tail pipe. When I stopped, it was idling rough. When I opened the hood, the CDR valve had blown right out of the valve cover and everything was splattered with oil. When idling, it sounds like a steam engine.
After reading a bunch of posts, I figured I had injector get stuck open and burned a hole in a piston.
I have been trying to sell it needing repairs. Today, I decided to try to find out what is wrong with it.
I cracked each injector open one at a time and they all make a big difference in the running.
I only have a compression tester for gas engine so the needle hits the peg at around 335 psi. I checked the 3 front driver side today and they all peg the gauge. I am going to find a higher pressure gauge tommorow and check them all but will have to pull the exhaust manifold on the turbo side to get the glow plugs out.

Is this enough info to get any ideas of what might have happened? I can post all the compression numbers after I get them if it will help.
Could it possibly be a head gasket? :confused:

Thanks
Dieselfume
08-07-2003, 00:29
What color smoke was coming from the tail pipe, white, black, or blue? What does the smoke smell like? Was there steam coming from the crankase through where the CDR used to be?

Is there oil in the coolant? Does it bubble air into the coolant resivior? Is there coolant in the oil? A good way to check water in oil is to wipe the dipstick on a hot exhaust manifold, if it sizzles it's got water, if it slowly steams away, it's just oil.

Could it possibly be a head gasket? yep, could be... Could be something else. That compression data would help. Has the engine been running hot lately? Do you have a temp gauge or idiot light?

Hope that helps!
rugger
08-07-2003, 09:36
where are you at in wisconsin you can borrow my compression testor or any tools i have? I'm in kenosha.
whatnot
08-07-2003, 10:29
I can't remember the color of the smoke but I think it was black. I haven't driven it much since it happened and it is kind of gray when cold.
I removed the radiator cap and there is no pressure or bubbles.
With it idling with the CDR valve out there is more smoke out of the valve cover than the tail pipe. I think that all the oil vapor being forced into the intake might be causing the tailpipe smoke.

rugger,
Thanks for the offer but I am near Madison.
I think I can find enough parts to make the one I have work.
whatnot
08-07-2003, 12:18
Well, it turns out I don't need a different gauge.
The front 3 on the passenger side are 175 PSI and the back one is 25 PSI. :(
I don't know how the back one could have been doing anything but I loosened the injector line several times and it always made a difference.
rumbler1
08-07-2003, 19:20
Whatnot, last year I developed a hole in #3 piston. I thought it was from a bad injector, but I had them all checked, and #3 was the best. With the hole in the piston, my breather tube blew clouds of smoke and there was a steady stream of black oil running through the Banks turbo (this is on a 86 6.2). It got so bad that it was blowing the dipstick out, and along with that lots of oil. In the end I rebuilt the whole engine and got a great running machine out of it.
Good luck!
whatnot
08-07-2003, 19:26
Whatnot, last year I developed a hole in #3 piston. I thought it was from a bad injector, but I had them all checked, and #3 was the best. With the hole in the piston, my breather tube blew clouds of smoke and there was a steady stream of black oil running through the Banks turbo (this is on a 86 6.2). It got so bad that it was blowing the dipstick out, and along with that lots of oil. In the end I rebuilt the whole engine and got a great running machine out of it.
Good luck!If it is a hole in the piston then are the other 3 cylinders with real low compression just a completely different problem?

I was hoping it might be either a head or head gasket. If it is likely a hole in the piston then I will probably just put it back together and try selling it broken again.
britannic
08-07-2003, 19:33
The front 3 on the passenger side are 175 PSI and the back one is 25 PSI.

Once the engine is running the rpms are considerably higher than when cranking and there's probably enough compression to fire the bad cylinder.
whatnot
08-08-2003, 08:30
How long would it take to pull the head?
I am still hoping it is the head but am afraid that I will get it apart and then see the whole engine needs to be replaced.

If I do end up replacing it, I would get a used engine. Is it worth the extra to get a 6.5 for $600 more than a 6.2?
rumbler1
08-08-2003, 15:51
Whatnot, I have no idea what tools you have available or how familiar you are with removing a head, but it took me around 9 hrs the first time I removed both heads from my 6.2 while in the Suburban. If you decide to do this it will be very helpful to use an engine hoist to lift the head off the block, as it is
pretty heavy and very clumsy to handle it. Also use the hoist to put it back on and you will have less chance of damaging the new head gasket. You may be able to remove it with the exhaust manifold still attached if using the hoist, which may save a little time. When I had my heads done it was discovered that all eight intake valves had been leaking, so it was definitely time to do the job. Good luck with this project.
whatnot
08-08-2003, 19:18
I am still deciding if I should do it. If it is more than the head then I don't know if I want to do any more with it.
The exhaust manifold is already off because it is the only way to get the glow plugs out.
I have an engine hoist that I figured I would need to use.
whatnot
08-12-2003, 14:08
I pulled the head last night.
http://www.rsixray.com/images/62piston.jpg
The picture is the back piston.
At least 2 of the other 3 have cracks in them. (I didn't look real close at them yet)
The cylinder walls have no grooves at all and are shiny. I can barely feel a ridge at the top. The engine has over 240K miles on it.

Would it be worth fixing or am I better off replacing it? If replace, is a 6.5 worth paying the extra for? Avant gave me a price of $1200 for a 6.2 or $1800 for a 6.5 + core and shipping on either.
britannic
08-12-2003, 14:50
Is Avant quoting for their used engines? The 6.5L would be the way to go if you can afford it, that way you can take advantage of the better designed more accessible heads and increased power.
whatnot
08-12-2003, 15:17
Yes, that is used tested engines with warranty.
I will either sell the truck or just use it for a spare to pull wagons around here after it is fixed so I don't want to spend a lot on it.
whatnot
08-13-2003, 23:12
I have pretty much decided to go with the 6.2.
I called them again today and I was off on the prices. There is $200 more difference in the price + a higher core charge for a 6.5.

I am thinking of selling the old engine in pieces either in the classified section here or on ebay.
Would there be enough sellable parts to do better than returning the core? (about $200 after shipping)
I have a J intake manifold on it and new injectors that I haven't decided if I want to more over yet. And I think the heads are good.
Is anything else on it worth anything?

Thanks for all the replies.