Engine issue - timing, chain, head gasket???

[trekuhl]

92 K1500

4.3

170K miles

 

bought this truck a few months ago for a winter-beater and just hauling big stuff round...only put a few thousand miles on it so don't know all the quirks like a long-time owner would.

 

dirving the other nite, put some extra gas on it coming out of gravel construciton area to kick up some rocks for fun and heard a loud strange noice, almost like scratching and tin foil being krinkled up real loud...the was also a TON of white (maybe grey it was nite time) smoke billowing from the exhaust. about 60 feet later the engine shut off so i pulled into closest lot to check her out...

 

The engine will turn over now, but not start. the spark seemed weak, so i replaced the cap, rotor, ignition coil with no luck. still is is yellow, not nice blue. (havent done wires yet though...)

 

thought at the time the soudn was busted belt, now thinking maybe it was the timing chain (slipping or breaking???) but the white smoke is throwinging me way off as well...thought maybe the head gasket went and collant leaked, but seemed very exessive for a blown head gasket, more like a crack in block letting it dump out. My thermostat hadnt worked since i bought the truck (hadnt had time tto try a new one either) and now it kicks all the way to the high side when i attempt to crank it (never did before) and i changed the oil a month ago, was setting right on the high mark, now it is three times to high (cracked block? - coolant seeped in?)

 

Anyone have any similar experiences with this truck? I was going to try setting TDC (have never done this on a V6) and check the rotor and see if the timing was off...IF the timing chain has failed/broken i would assume the engine wouldnt be turning over, but if it slipped it may and the timing would just be off...but the amount of noise that it made (if thats what it was) would lead me to believe the sprocket would most likely be shot, or the chain severely stretched

 

Sorry - i am not too familiar with this engine, most of the cars i have owned (and worked on) have been imports.

 

 

thanks for anyone who can understand my ramblings...

 

-Trey

[Haulin' 8.1]

Holy cow that is a lot of ramblings there Trey, but the more the better when trying to get help for something sight unseen. Well I can't tell you what the problem is from all that but I can offer some help from what you've said. Mainly, don't beat on a engine with that many miles on it without knowing it's history, but I think you may have figured that out already though . These engines usually go through a distributor at least once in thier life.

 

First just to rule out the broken block or blown head gasket theory do this, bring a bottle of oil and then remove the oil drain plug for just a second, if your hand gets covered with oil you're fine, just put it back and top it off. But if it gets wet, put a fork in it as it's done. The oil floats on water so if the internals are kaput all the waters down there where your dipstick may not reach. Make sure you can see it coming out.

 

The fact that you're getting a spark at all means your timing chain is still intact, it turns the camshaft which drives the distributor on its other end. The turning distributor generates the signal for spark. So your chain is there, and the cam and distributor aren't broken either. Now it may be stripped but not likely. Stripped gears make noise for a long while while going away. If yours was in that shape you wouldn't have bought it a couple of months ago due to the racket.

 

All sparks must travel through the coil to distributor wire, if it goes out it will weaken all the sparks at a ever increasing rate until it dies suddenly. See if you can scrounge a known good single lead to replace the coil wire for testing (no need buying a new wire set for an engine that may be a lump of scrap at this point).

 

If spark goes away or wimps out at WOT you'll dump a bunch of fuel into the exhaust system until the RPMs fall or you let off the throttle. This can cause a thick cloud of white smoke if your convertor wasn't hot enough to burn it yet.

 

If it's still got a weak spark with a fresh coil lead suspect the distributor. There are three components in its housing. The SHAFT, the shaft spins in bushings in the housing and when they wear down enough the shaft can strike the PICK-UP COIL. The pick-up coil is what generates the signal for the IGNITION MODULE (ignitor in import speak). The module turns on and off the coil based on the trigger signal it gets from the pick-up. When the pick-up gives it will make a weak or erratic spark at best. Since all three of these things come with a remanufactured distributor and replacing two of them when you have worn bushings only breaks more parts, wastes more money etc. you should replace the whole assembly at once to get your truck running again.

 

The bad news is that it'll go in about 50 ways and only one is correct. Move the cap asside and get the rotor pointing straight ahead by bumping the starter and tugging the belts. At this point remove the key and don't turn the crank until you're done. Then make note of the distributor housings relative alignment to the rest of the engine. Unplug the wireing on the back side. Remove the 9/16" bolt and cleat bracket from the Pass side of the distributor at the engine block surface. Wiggle and pull the distributor straight up. The rotor will rotate counter clockwise slightly on the way up, make note of exactly how far. Transfer the rotor to the new distributor. Take the new distributor and slide it down with the rotor starting in the same spot the old one stopped. Once it starts enguaging the gear wiggle the mess around until it fits all the way down with the rotor pointed straight ahead again. Now rotate the housing until it's in the same position as the old one was relative to the rest of the engine (as good as you can eyeball it). Put the cleat and bolt back in and snug it up. Put the cap and wires back on. If you have a timing light and know how to use it now is the time. You'll need a manual to tell you the procedure as there's a wire under the glove box you'll have to disconnect to set timing. If not it will probably be close enough to get it to someone who can, if you go there first. Put the wire, cap, and plug wires back on double checking the firing order. If you did it right it should fire up now.

 

Hopefully this will get it going again as in my experienced opinion the distributor is the most likely culprit.

 

Vernon

[trekuhl]

i was able to get a friend with his c1500 to pull my k1500 back to my house...

 

we looked it over a bit. i had starting pulling spark plugs 1 and 3...

 

1 had some aluminum and stuff on it and even under the contact...possibly part of the piston i think

 

3 was soaked and the contact was smashed to the point. It was soaked in what i think is coolant. is was not viscous enough to be oil ( i just changed the oil less than 1K ago with 20-50, heavier cuz i had a ticking in the engine) nor did it smell of gasoline.

 

at that point i gave up. i think i mentioned earlier in my post that the oil level was absurdly high (coolant?) and i think the engine was flooded with coolant.

 

I am thinkin at this point about getting a reman engine. This engine was tired already and i only bought the truck cuz i got a decent deal on it (bought off ebay, course after tires and exhaust work that deal didnt seem so sweet anymore...) but the body has quite a bit of rust. with the amount of $$ i have in it, i would lose a ton if got rid of it, even if got a junkyard engine and sold it i would probably only break even. if i pop a reman engine myself and probably run it for another 6 years (provided the body doesnt rust out on me)

 

lesson learned. ebay deal = bah.

 

i had already tried a few of the things you had mentioned, but i will also try pulling the drain plug and seeing it i can absoutely verify coolant in there.

[Wingnut]

Dang, take it apart and post some pics..

 

 

 

Seriously though, sorry to hear it.

 

 

And just remember "It's all fun and games until somebody loses an engine".

[sjspor]

Hmm... From the inital ramblings, I was thinking the timing chain jumped. But if you have metal on a spark plug.. Well, At least drain the oil and see if you get chunks, or pull a valve cover.

 

I would'nt bother with E-bay for a motor, just a hit a junkie. There are tons of these motors out there. If you did jump time, the motor will may stumble when cranking. The plastic coated gear will break a tooth and the chain will jump.

[trekuhl]

i just ordered a reman engine $1200 plus the guy delivers and picks up the old one for no extra charge. isnt charging core fee, just $60 sales tax and i dont even pay till he comes to pick up the old motor...

 

the time it would take to pull the old one apart just isnt worth it when i dont know the history on it. time i could spend working will more than make up for cost of a new engine...besides now i have the ultimate truck - engine thats practically new and a body that looks like hell so need to worry bout anyone bangin her up in a parking lot or anything...

 

 

now if only the interior were in good shape...

[builderpaul]

i was able to get a friend with his c1500 to pull my k1500 back to my house...

 

we looked it over a bit. i had starting pulling spark plugs 1 and 3...

 

1 had some aluminum and stuff on it and even under the contact...possibly part of the piston i think

 

3 was soaked and the contact was smashed to the point. It was soaked in what i think is coolant. is was not viscous enough to be oil ( i just changed the oil less than 1K ago with 20-50, heavier cuz i had a ticking in the engine) nor did it smell of gasoline.

 

at that point i gave up. i think i mentioned earlier in my post that the oil level was absurdly high (coolant?) and i think the engine was flooded with coolant.

 

I am thinkin at this point about getting a reman engine. This engine was tired already and i only bought the truck cuz i got a decent deal on it (bought off ebay, course after tires and exhaust work that deal didnt seem so sweet anymore...) but the body has quite a bit of rust.  with the amount of $$ i have in it, i would lose a ton if got rid of it, even if got a junkyard engine and sold it i would probably only break even. if i pop a reman engine myself and probably run it for another 6 years (provided the body doesnt rust out on me)

 

lesson learned. ebay deal = bah.

 

i had already tried a few of the things you had mentioned, but i will also try pulling the drain plug and seeing it i can absoutely verify coolant in there.

 

<{POST_SNAPBACK}>

 

 

 

If plug was smashed it means you "though a rod". Piston came up and hit plug. It also busted into the cooling chamber so block is shot. Nothing to do with timing chain, head gasket, or ignition system.

A crate engine comes with factory warranty but it sounds like the truck is not really worth it.

A re manufactured is a little cheaper but not much.

If you can hear a junker run and verify the mileage that sounds like the best way to go.

With all the work involved on a rusted out winter beater I would take the loss and find a different truck.