TRusselo
Junior Member
- Joined
- Dec 13, 2013
- Posts
- 5
- Reaction score
- 0
- Ram Year
- 1997
- Engine
- 5.2 Magnum
I initially started this at another forum, got nowhere, so there's a bit of catching up to do...
===============
I will admit Im no engine guy, but my best friend who's been a licensed mechanic for 10 years helped me. Just replaced the head gaskets, (whole top end gasket kit), and timing set, plugs wires. Painted everything too.
Got it all back together, fires right up cold, a little rough, almost seems like a missfire, but not horrible by any means, gets warm we revved up to 2500 and starts running like crap, revs all over the place, evens out, kinda, then touch the gas again - the smallest touch - and it dies. Wont run again while warm unless full throttle, and even then it runs like crap.
Let it cool down, and it ran at idle again. touch the throttle, and it dies again. wont start back up at all.
Seems like a timing issue, we are pretty dam sure that the timing set was installed an aligned correctly. old set off, new set on within 3 minutes, no ******* around, 2 people checked the marks in line, then installed.
The old chain had a SURPRISING amount of slack, 1/4 inch! , the engine ran fine before, besides overheating, the only reason we were changing the timing set was because, Why not? 310000km unknown history, and we are 6 small bolts away. change it while we are there.
Never removed, loosed or touched distributor, only changed cap while the intake manifold was off, when it is the absolute easiest on these engines.Through a timing light on just for reference, its 15-20 degrees off at idle...
Please help me work through this. its been 2 days, cant figure anything out, and my mechanic is stumped... at least give me some spit ball ideas.
BTW i have alldata on my computer. yes all 319 GB of it.
==============
i have only owned this truck about 2 weeks, wrapped my last one around a pole, i dont have much of a history on the truck, but looks like it has been taken to dealership for work, fog light wiring harness looks NEW, there is a Dealership Authorized Change sticker on the fuse box under the hood saying that the PCM has been changed out with another unit, date 08-97. truck would have been few months old then,
=================
Someone Suggests checking distributor indexing/cam sensor alignment.
got fuel pressure. got good vacuum. every gasket except oil pan was replaced new, even intake manifold bedpan gasket, and fuel injector o-rings were done.
I'll check the distributor indexing
====================
you mean like this? yup she's off a bit. rotor is sitting just before the mark at TDC.
Ill see if i can get my hand back there after a fresh pot of coffee
Is it worth mentioning that i get no engine codes, i know it hasnt run long to preform any diag, but... wouldnt a bad crank sensor send a code right away? thats what i'm considering tackling next, if the distributor doesnt fix it.
====================
well, adjusted the distributor, its bang on at TDC,
now it wont even start cold. im stumped.
screw it, time to rip off the timing cover to see if we were too tired to see straight that night.
===================
ripped off the timing cover, timing set is good, in line.
any suggestions?
=====================
Someone suggests a bad coil
got spark, compression and fuel.
========================
just noticed my new plugs are burnt and fuel washed (still after 18 hours of not turning over...). probably should have checked them after adjusting the distributor, when the engine stopped starting at all, before ripping my timing cover back off
=======================
pulled the intake, found bent rods, swapping the heads with 5.9 heads and rods i have sitting in the garage. Start from scratch. See if Mopac has a cam in-stock. Might as well at this point.
==========================
Started cleaning up the 5.9 heads to install, and found a crack in the head in the seat of the first valve we removed. Scrap that idea. At least we found it on the first valve and not the 16th.
tore the whole top end apart, inspected all valves (original 5.2 ones), guides, lifters and rods.
Found 4 bent rods intake and exhaust on cylinder 1 and 6. And found impact marks on the pistons 1 and 6 where the valves hit. no cracks in the pistons but 2 nice shiny moon shapes about 5/8 long on 1 and 6. there was also several blown valve guides.
no damage to the valves. lapped the valves, cleaned the heads, re-installed the heads, new rods, inspected movement by rotating engine by hand.
Could not find a reason for the valve impacts/bent rods. Timing was correct. and only on 2 cylinders, running mates, both intake and exhaust.
Did 4 of 16 lobes magically move or change shape? Did cylinders 1 and 6 decided to come up too soon AND stay up too late? (sarcasm) wtf?
Timing and movement of crank, cam, distributor, rods, valves ALL IN SYNC.
Re-assemble engine, starts right up, runs for 15 minutes, touched the throttle and DIES. No noises no nothing just died. Ran fine. dies.
Will not start back up.
Towing to dealership tomorrow.
======================
Anyone here have any ideas what the hell is going on?
The most confusing part is all 4 valves on only 1 and 6... and no evidence of why... plus why it wont run.
===============
I will admit Im no engine guy, but my best friend who's been a licensed mechanic for 10 years helped me. Just replaced the head gaskets, (whole top end gasket kit), and timing set, plugs wires. Painted everything too.
Got it all back together, fires right up cold, a little rough, almost seems like a missfire, but not horrible by any means, gets warm we revved up to 2500 and starts running like crap, revs all over the place, evens out, kinda, then touch the gas again - the smallest touch - and it dies. Wont run again while warm unless full throttle, and even then it runs like crap.
Let it cool down, and it ran at idle again. touch the throttle, and it dies again. wont start back up at all.
Seems like a timing issue, we are pretty dam sure that the timing set was installed an aligned correctly. old set off, new set on within 3 minutes, no ******* around, 2 people checked the marks in line, then installed.
The old chain had a SURPRISING amount of slack, 1/4 inch! , the engine ran fine before, besides overheating, the only reason we were changing the timing set was because, Why not? 310000km unknown history, and we are 6 small bolts away. change it while we are there.
Never removed, loosed or touched distributor, only changed cap while the intake manifold was off, when it is the absolute easiest on these engines.Through a timing light on just for reference, its 15-20 degrees off at idle...
Please help me work through this. its been 2 days, cant figure anything out, and my mechanic is stumped... at least give me some spit ball ideas.
BTW i have alldata on my computer. yes all 319 GB of it.
==============
i have only owned this truck about 2 weeks, wrapped my last one around a pole, i dont have much of a history on the truck, but looks like it has been taken to dealership for work, fog light wiring harness looks NEW, there is a Dealership Authorized Change sticker on the fuse box under the hood saying that the PCM has been changed out with another unit, date 08-97. truck would have been few months old then,
=================
Someone Suggests checking distributor indexing/cam sensor alignment.
got fuel pressure. got good vacuum. every gasket except oil pan was replaced new, even intake manifold bedpan gasket, and fuel injector o-rings were done.
I'll check the distributor indexing
====================
you mean like this? yup she's off a bit. rotor is sitting just before the mark at TDC.
Ill see if i can get my hand back there after a fresh pot of coffee
Is it worth mentioning that i get no engine codes, i know it hasnt run long to preform any diag, but... wouldnt a bad crank sensor send a code right away? thats what i'm considering tackling next, if the distributor doesnt fix it.
====================
well, adjusted the distributor, its bang on at TDC,
now it wont even start cold. im stumped.
screw it, time to rip off the timing cover to see if we were too tired to see straight that night.
===================
ripped off the timing cover, timing set is good, in line.
any suggestions?
=====================
Someone suggests a bad coil
got spark, compression and fuel.
========================
just noticed my new plugs are burnt and fuel washed (still after 18 hours of not turning over...). probably should have checked them after adjusting the distributor, when the engine stopped starting at all, before ripping my timing cover back off
=======================
pulled the intake, found bent rods, swapping the heads with 5.9 heads and rods i have sitting in the garage. Start from scratch. See if Mopac has a cam in-stock. Might as well at this point.
==========================
Started cleaning up the 5.9 heads to install, and found a crack in the head in the seat of the first valve we removed. Scrap that idea. At least we found it on the first valve and not the 16th.
tore the whole top end apart, inspected all valves (original 5.2 ones), guides, lifters and rods.
Found 4 bent rods intake and exhaust on cylinder 1 and 6. And found impact marks on the pistons 1 and 6 where the valves hit. no cracks in the pistons but 2 nice shiny moon shapes about 5/8 long on 1 and 6. there was also several blown valve guides.
no damage to the valves. lapped the valves, cleaned the heads, re-installed the heads, new rods, inspected movement by rotating engine by hand.
Could not find a reason for the valve impacts/bent rods. Timing was correct. and only on 2 cylinders, running mates, both intake and exhaust.
Did 4 of 16 lobes magically move or change shape? Did cylinders 1 and 6 decided to come up too soon AND stay up too late? (sarcasm) wtf?
Timing and movement of crank, cam, distributor, rods, valves ALL IN SYNC.
Re-assemble engine, starts right up, runs for 15 minutes, touched the throttle and DIES. No noises no nothing just died. Ran fine. dies.
Will not start back up.
Towing to dealership tomorrow.
======================
Anyone here have any ideas what the hell is going on?
The most confusing part is all 4 valves on only 1 and 6... and no evidence of why... plus why it wont run.