'90 Plymouth Voyager engine noise
#1
'90 Plymouth Voyager engine noise
Please help! I have been given a 1990 Plymouth Voyager SE with 3.8l v-6, automatic overdrive trans and about 120,000 miles. I am told it had the timing chain replaced shortly before it was parked. It was benched due to driveability problems(stalling, stumbling). I can get the engine to start and run, but it makes a horrific rattling noise in the passenger side/rear area of the engine. The noise follows engine RPM until engine revs fast enough that the noise goes away. The engine also doesn't want to idle. I don't have much experience with this engine or manufacturer. I also haven't put in a lot of diagnostic time on this particular vehicle. I was thinking of trying to isolate the noise by removing the serpentine belt and seeing if the noise continued. My thinking is that this would tell me at least whether the engine was at fault or one(or more) of the accessories. When I get to start it, it's with a pirated battery, so unless codes are hard-stored, I won't be able to retrieve them just yet. Any help would be greatly appreciated - this minivan is in good shape bodywise, and would make a useful addition to my stable if I can afford to fix it! Thanks for help - Chris
#2
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is the engine missing or does it appear to be running good other than not idling?
might try cleaning the throttle plate and seeing if it will idle afterwards, and removing the belt to see if noise is still heard is a good idea, if the noise does go away spin each pulley by hand and try to determine where its coming from.
might also have a local shop listen to it can probably tell you the general vicinity if it is internal such as lower end noise or valvetrain noise.
might try cleaning the throttle plate and seeing if it will idle afterwards, and removing the belt to see if noise is still heard is a good idea, if the noise does go away spin each pulley by hand and try to determine where its coming from.
might also have a local shop listen to it can probably tell you the general vicinity if it is internal such as lower end noise or valvetrain noise.
#3
Decribe the noise better. Is it a rapping/thunking? If so, might have internal engine failure. An engine oil pressure check with a gauge could reveal that.
If so, stop here. Pitch the vehicle and cut your losses. (none at this point it seems), or replace the engine with a used one.
If so, stop here. Pitch the vehicle and cut your losses. (none at this point it seems), or replace the engine with a used one.
#4
The engine noise sounds a lot like banging a couple of pieces of steel plate together. Frequency(not pitch) goes up as RPM's go up until about 3000-3500. It sounds(to my untrained ear) like it's coming from outside the engine, but some of that may be wishful thinking. The oil pressure question had crossed my mind; can you enlighten me as to where I would find a port to hook up a gauge? Also, isn't the oil pump inside the timing cover on this engine? If so, seems it would be a simple fix, assuming no internal damage has occurred. I appreciate everyone's help and feel the same as at least one other member has said - this forum rocks! Let me know if you have any other ideas based on this information. Thanks again - Chris
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Check the oil pressure, but since this was benched for the idle problem than I would consider doing a compression check, both wet and dry. You need to try to pull codes while you have the spare battery in it, just to see if it helps. Your idea about removing the serpentine belt is a good one. Also check for broken motor/tranny mounts and anything loose in the exhaust system. I would diagnose that idle and any oil pressure problem first before going too much further.
#7
90 plymouth voyager engine noise
need to isolate noise. sounds like valvetrain noise... rec. large screwdriver handle to your ear then to valve cover...if one head is louder than the other..rec. removing that valve cover.(for rear cover, plenum must be removed...not hard to do) then inspect for lack of oil to rockers & valve train area. if it looks dry it has a spun cam bearing (not good!) if it has oil check rocker shaft stands (part of cyl. head...aluminum....cracks) then you need a reman head (not to bad)...these are common problems with these engines with high milage..good luck.
#8
Thanks to Stevo2 and the caller. I'm anxious to get the van home and try to figure this all out. You've all given me logical advice. I'll post as soon as I can and let you know what pans out. Thanks again - Chris