Re: 97 Suburban major engine problem

You washed the air filter? On or off the truck ;) You cant do that, well er.. I guess you did.

Sounds like the water has worked its way in to the ignition system. Does this Vortec have a Cap and rotor? If so, dry it out. Also inspect the wires.

If you got water into the intake you might have caused hydro lock when you started it. That can cause a cracked head, block, and other problems.

Cheers

I went through much hell with my S10 waste spark system until i realized the plug wires could make it run that bad. (I had MCM too on a code scan) Worse when it was damp or wet. I would put new set of FACTORY wires on it and change the plugs. Inspect the plugs while you at it for signs of deposits (shows which are misfiring). Look closely for any vacuum hose that might have come disconnected or accidentally cut. Maybe you will get lucky?

Bob

My Name wrote:

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I did not get anything wet other than the air cleaner and that was damp not soaked. Nothing near the distributor or spark plug wires is wet. I recently replaced the wires and plugs. I did remove the number one plug and looked at it to see that it still has the proper gap (platinum plugs)...the plug is dry and covered with black soot. I am planning on removing the plugs tomorrow (I would have done it sooner but my back went out on me six days ago......like the engine problem isn't enough) and check out the compression on each cylinder. One thing that is really puzzling me is the fact that it starts up so easy.

Thanks for your input MJ

this Vortec have a Cap and

started it. That can

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One of the few things that I am sure of it that the plug wires are dry. I will remove the plugs and inspect for any cylinders that are different than others.

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As I have said to others, nothing is wet. The engine has never been washed. The friendly dealer says that I need a new engine. I could be wrong but it seems to me that after installing a new engine I am going to have the same problem. As far as I know new engines don't come with CSFI fuel injector systems or throttle bodys.

do a compression and leak down test. if something is wrong that is THE way to find out without pulling it apart.

One thing i did on my s10 was to put my timing light on each plug wire to check for output. On the defective ones, it would not flash as bright or was intermittently flashing. A cheap a quick test for dead or intermittent firing. Not fool proof, but it found my bad ones. Could be a bad coil pack too. I take it you coolant sensors checked ok on the scans? A stuck coolant sensor could tell the computer the engine was ice cold and rich up the mixture. Or maybe a intermittent connection on the sensor? You might find out where it is and check the connection for corrosion. Would not be that expensive to change out. Note: this sensor may NOT be the one the controls the temp gauge on the dash.

BOB

Any time a vehicle develops a (new) symptom after a 'repair' the first thing to suspect is the repair itself. It rains on cars and MAF sensors get wet all the time and the vehicle still runs OK. I would look very hard at vacuum lines knocked loose, disconnected wiring, etc. Keep in mind that the person who did the repair is going to have the hardest time finding such a fault as it was overlooked the first time.

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Now we know it's running rich.

The MAP sensor is only used in running the EGR diagnostic on this engine. I doubt that it could be the cause of any drivability concern unless the vacuum hose itself were leaking.

That was indicated by the black plugs.

I'm surprised there are no other codes indicated as the MIL on steady would seem to suggest this. The blinking MIL is an indication that engine misfire has been detected.

This may seem obvious and you probably already considered it. You spent a lot of money already and surely went over everything that you touched. My question is just how wet did you get this air cleaner when you washed it? If that paper was wet when you started it up there just could have been enough water pulled into a cylinder to bend a rod or two. It really takes very little and water could have been hanging in the pleats ready to get sucked in. Experience shows that you can drive into a puddle and stall an engine due to water. Dry everything out completely and replace the filter and you are OK. Try to start the engine with that wet filter and the engine can be toast. That is essentially what you say you did. Do your own compression test and you will know the answer.

I did something like that on my motorcycle... I over oiled the K&N air filter, instant plug fouling and it barely idled, giving it gas would make the engine bog real bad. I removed and re cleaned/oiled the filter and it still ran crappy. My spark plugs were blackened and fouled to the point that even with a clean filter it wouldn't run. Replaced the fouled plugs and fixed it right up. Have you replaced the spark plugs?

Follow up to all that have helped and anyone else interested...........After checking the compression I found that on the left head the compressions were

60lb., 140, 90, and 120. On the right all cylinders were 185lb. I have a new long block ordered and have the engine removed. The only thing that I am still worried about is what caused this to happen in the first place? I am very suspecious that the damage was caused by water getting onto the MAF sensor, shorting it out, and changing the settings in the ECM, that in turn caused the engine to run way out of time.

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My father in law routinely pours water into the carb of his 366 chevy, while running, to decarbonize the combustion chambers. Old school mechanics have been doing this for many many years. There are other commercially available products that are designed to be used the same way. I think it is highly unlikely that he hydrolocked his engine with a damp air filter.

Dave

I've done that also. He didn't do that.

I think that when he started the engine, the differential air pressure across the soaking-wet paper filter (that was NEVER intended to get wet in the first place) caused a substantial slug of water to be ingested into the engine at a very low RPM. Perfect conditions for hydraulic lock. Just guessing, I'd say that a typical pleated paper air filter, saturated, might hold close to cup of water (remember there is a LOT of paper in there and its very porous to start with). If just HALF of that was suddenly sucked into the engine on start-up, the potential for disaster is huge.