M35A3 execessive blowby and blue smoke on decel

[unispeed]

M35A3 excessive blow by and blue smoke on de accel... Well I think (know) something gave on the Cat in the M35a3) I have excessive blow by (crankcase pressure) and when rolling and you let up on the pedal really blue smoke in the exhaust
What would you do? think this can be salvageable? take it to a diesel mechanic or the cat house?

Or just get another a3 and save this one for parts?
I was hoping someone might have a magic trick to check …..but after reading these engines appear to be throw aways….. it just burns 1qt hour
but it is still strong
Mark

the only bad piece up front was the fan belt broke and it got hot but the smoke did not appear till after 4 hr of tach time??
and yes don't let your brother in law drive it!

 

[autigers35a3]

How hot did it get?
Still have power?
I think the blue smoke = oil. Not sure

 

[BadMastard]

I'm just guessing here, but if you had an overheat you probably have a head gasket leak. TM 9-2320-386-24-1-2 engine maintenance covers the procedure for cylinder head removal and replacement. So, to answer your question, check it. If you think you can do it, go for it. If not, take it to a cat mech and ask how much. I'd love to have a parts truck, but I'd love driving it even more. Good Luck!

 

[firefirefire90]

I'm just guessing here, but if you had an overheat you probably have a head gasket leak. TM 9-2320-386-24-1-2 engine maintenance covers the procedure for cylinder head removal and replacement. So, to answer your question, check it. If you think you can do it, go for it. If not, take it to a cat mech and ask how much. I'd love to have a parts truck, but I'd love driving it even more. Good Luck!

a leak in the headgasket would explain white smoke, not blue.

 

[autigers35a3]

valve seals/oil = blue ???

 

[BadMastard]

Hmm. White smoke if it's pushing out coolant, but if it's blowing oil then it'd be blue yes? Other option I'd think was the turbo seals going out/wearing out and pushing oil in with the compressed air. But I could be wrong about the head gasket. Again, just guessing.

 

[1 Patriot-of-many]

What I learned in tech school and in regular life blue smoke, oil burning. rings ,valves, valve seals, I suppose turbo seal too could be dumping oil in the exhaust. In any case oil IMO. If you're running fine check your oil level frequently, my bet is it will start decreasing more than normal as most indicated.

 

[Varyag]

You can sometimes tell bad rings by seeing how much blow by is happening in the crank by pulling the oil cap while it is running.

 

[Rustygears]

Your symptoms indicate crankcase oil and the little comment at the end confirms it. You've popped a head gasket. They most often fail due to overheating. The failure is one of three ways: white smoke - coolant in the bores, blue smoke - lube oil in the bores or megafroth in the cooling system due to lube oil in the cooling system. The blue smoke scenario is really common. Check for oil in the coolant as well.

 

[unispeed]

Thanks for all the replies!
I was thinking rings (cause there is blowby by in the case) smake a pressure when fill cap removed duing idle
also the breather tube down below smokes all the time
but then I had a chevy454 that would smoke when you let off the gas (it was valve stem) at the high vacuum would suck the oil by.... but turbo charged diesels are new to me..
Hiw hot did it it?
I was not driving but the temp guage i heard was pegged and the radiater released some steam..
but it did no go bone dry and the pump was still circulatimg (just the fan belt)
Wouldn't you think that if the heat warped or stressed something that if would have showed up before 4 hrs of runtime on the engine?

And there is plenty of power see no difference in power.....

Mark

 

[klsmith925]

check your turbo out check all the seals the oil seal could be bad putting oil in the engine but it could have been a head gasket to its hard to tell unless you take a look at her blue smoke is oil burning

 

[BadMastard]

Also, check your alternator bracket. Mine broke, many do as it's a poor design. It was the weld on the front of the bracket where it connects to the block. It's u shaped, one side is welded, and that's the side that breaks. If you lost your serpentine belt, it's likely to have put extra force on during release. Easy to fix, I think eastern or c and c has an updated bracket.

 

[glcaines]

The CAT 3116 engine isn't a throwaway engine. People call it that because it is a sleeveless engine which means that when it is rebuilt, you cannot replace the sleeves. Most of the M35A3s out there have very little mileage on them and it is very unlikely that most people with A3s would drive them enough to wear out the engine.

A very good source for information on CAT engines, including the 3116, is Caterpillar On-line. This is a forum for professional CAT mechanics, but they let anyone join. The URL is: https://caterpillar.lithium.com/ . You can find some very good reading there and post questions. I would agree with others that you probably have a blown head gasket. If you are mechanically inclined, go for it. Otherwise, have a CAT mechanic work on it. As a side note, the 3116 engine in A3s is supposed to have the top end serviced at 500 hours. If yours is at or near 500 hours, this would be done as well during the head gasket replacement.

 

[unispeed]

Gary,
You think a head gasket would cause blow by
the biggest reason i want to be so sure is that I dought i will pull the engine where is sits (but i could do the head) i can drive it to a shop as is ....but not if the head is off (i guess i could always put it back on i lue of towing)

did you see this info on a cat 3116 sleeves??????????????
are these new or for some other engine than ours?


http://www.mellingcylindersleeves.c...cleId/113/New-Sleeve-for-CAT-3116-Engine.aspx

Caterpillar 3116 Engine Rebuild Kit (IPD One Piece Piston)

This Engine Kit contains one piece aluminum pistons. Oversize pistons are not available for this application. Please refer to Caterpillar Service Bulletin SEBF8261 for the recommended procedures on installing cylinder salvage sleeves. The part number for the salvage repair sleeve is 7C6208. This Engine Kit contains one piece aluminum pistons. Oversize pistons are not available for this application. Please refer to Caterpillar Service Bulletin SEBF8261 for the recommended procedures on installing cylinder salvage sleeves. The part number for the salvage repair sleeve is 7C6208

 

[Rustygears]

A blown head gasket can cause blowby as well as combustion products in coolant. Both are due to compression loss. Head gasket failure doesn't require radiator to go dry. That would cause engine seize. Any time the engine temp goes super high and the radiator boils over, the head gasket is a candidate for failure. That failure does not necessarily become noticeable immediately. The failure can be progressive and get worse over time. Typically, only 1 cylinder is affected and the engine may still develop what appears to be full power. Running it in this condition should be avoided if possible.

 

[glcaines]

Gary,
You think a head gasket would cause blow by
the biggest reason i want to be so sure is that I dought i will pull the engine where is sits (but i could do the head) i can drive it to a shop as is ....but not if the head is off (i guess i could always put it back on i lue of towing)

did you see this info on a cat 3116 sleeves??????????????
are these new or for some other engine than ours?


http://www.mellingcylindersleeves.c...cleId/113/New-Sleeve-for-CAT-3116-Engine.aspx

Caterpillar 3116 Engine Rebuild Kit (IPD One Piece Piston)

This Engine Kit contains one piece aluminum pistons. Oversize pistons are not available for this application. Please refer to Caterpillar Service Bulletin SEBF8261 for the recommended procedures on installing cylinder salvage sleeves. The part number for the salvage repair sleeve is 7C6208. This Engine Kit contains one piece aluminum pistons. Oversize pistons are not available for this application. Please refer to Caterpillar Service Bulletin SEBF8261 for the recommended procedures on installing cylinder salvage sleeves. The part number for the salvage repair sleeve is 7C6208

That is very interesting. I need to do some research. I've been told by more than one source that 3116 engines do not have sleeves. Perhaps I'm mistaken.

 

[autigers35a3]

Cat mechanic time ... DO NOT DRIVE IT!!! I would not drive it untill checked out!!

 

[goodguyzy]

im also going with head gasket, when I lost my oil through my turbo (m35a2) I had white smoke.

 

[firefirefire90]

A blown head gasket can cause blowby as well as combustion products in coolant. Both are due to compression loss. Head gasket failure doesn't require radiator to go dry. That would cause engine seize. Any time the engine temp goes super high and the radiator boils over, the head gasket is a candidate for failure. That failure does not necessarily become noticeable immediately. The failure can be progressive and get worse over time. Typically, only 1 cylinder is affected and the engine may still develop what appears to be full power. Running it in this condition should be avoided if possible.

hmm... interesting. I havea 6.2 CUCV engine with only 18k on the engine, and it has blowby in two cylinders. Could this be a headgasket?

 

[garp]

3116's have no sleeves from new. when you rebuild one, the block is bored and sleeved back to standard. this is done with a torque plate bolted on the deck so the block is stressed properly. If this is not done, bad crap happens when the engine goes back to work.

Is your blowby a puff or a steady stream? A puff usually indicates a scored cylinder. A steady stream may be from a failed turbo, boost dumping down the drain into the crankcase. Or the head gasket could be blown out into the area where the push rods pass thru. Pull the valve cover off and fire it up, see what you can see.

Another thing for folks to remember. head gaskets are subject to deteriorate due to age more than anything. So with some of these engine nearing 20yrs of age, head gaskets will be an issue.