Sounds like a diesel

[Red's]

At start up everything works and sounds properly on my '88 Grand Wagoneer. But after it warms up and it has been driven for a few minutes, it starts sounding like a diesel engine or a lawn mower even. The sound starts when the engine is revving at high RPM and goes away when it changes gears. Progressively, it becomes worse and eventually it will sound like a diesel continously until the engine cools down. The sound has, however, dissapeared all together (while hot and running) before and come back only minutes later. I thought it was a hole in the exhaust system, but then again, that it can come and go is very strange. I know that there is a small hole in one of the emission tubes. Also, the engine does have 170,000+ miles on it. Any ideas on what this could be? Could it be the exhaust? Thanks for your input and any possible troubleshooting and solutions.

[gsmikie]

check the torque converter bolts and the flex plate

[Brown Bear]

You might want to check your plugs, see if they're running hot. You might be running too lean.

[Red's]

The noise just gets louder and louder. I took the plate off to see the flywheel there. I tapped it and listened and didn't really hear much of a ping other than metal to metal. How else can I troubleshoot this? Consider me an amateur when it comes to mechanics. If the torque converter (that being what I see inside the bellhousing when I take the small cover off) is cracked or bad, does this mean that the only solution is taking the transfer case out and transmission out or taking the engine out and working from that end?

[Brown Bear]

turn the flywheel around, and using a socket wrench, and a screwdriver to hold the flywheel in place, make sure that all the bolts connecting the flywheel to the torque converter are tight. Mine have worked loose more than once, and they don't have to loosen much for there to be some major chatter.

[Red's]

OK, sorry to ask a silly question, but just want to make sure that I am doing all of this correctly. I take the small plate off of the bellhousing. I should also take the starter off and take the plate that it is on off? The Haynes manual I have doesn't cover much on the automatic transmissions because they say that only professionals should do this. THanks again for all your input. The more specific you are the better. Don't what I would do without this site.

[gsmikie]

take the small plate off of the bellhousing.....you do not have take the starter off and the plate that it is on off then check the bolts that hold the converter to the flex plate and make sure they are tight there are 4 of them

[Red's]

OK, ao I went in there and tightened the four bolts. It was tough since the wheel has be rotated in order to get to the next bolt. After I made sure that they were all tight (which they were for the most part already) I started it up and still heard some of the noise. After about two minutes it wnet away, and I have never heard my truck run better. So I got in it and drove it around...once the truck really warmed up, the chatter came back worse than ever... what gives? If I have to replace the torque converter I think this is the end for this wagoneer... :(

[89grand]

Is this chatter you're hearing coming from the engine? If it is, it sounds like you are experiencing pinging. Try retarding the ignition timing and drive it again if the noise is reduced then you have either a timing problem or an over advance condition which is contributed to the vacuum advance or mechanical advance. I'm curently troubleshooting a pinging problem myself and was able to almost eliminate it by disconnecting the vacuum advance so I have a problem with the mechanical advance springs and or the vacuum advance canister. A hotter engine will always ping more then when it's cool if you have one of the above mentioned problems.

[Red's]

So, off I went to check all the vacuum stuff. I doubt if has anything to do with the distributor since I replaced it very recently with an MSD AMC distributor. I changed the black thing (sorry don't know and couldn't find the name for it) where a bunch of vacuum cables go to. This black cylindrical object sits right behind the battery. I had another one sitting around from another Jeep. I found that one of the vacuum motors that is in the outlet for the air cleaner is all loose and probably not functioning right. Could this be the source of the issue? It seems like something really small, and to me, insignificant. Thanks for your help.

[89grand]

Actually recently changing the distributor is probably where the problems is at. I just changed mine the other day and had pinging problems afterwards. I think I have narrowed it down to the mechanical advance springs being to light and some adjustment to the vacuum advance are needed as well.

That vacuum canister thing is the charcoal canister and is for emissions purposes so unless you have vacuum leaks there it probably isn't related to you problem.

[ July 02, 2003, 05:14 PM: Message edited by: 89grand ]

[Red's]

I changed the distributor about six months ago... I really don't think that is where it could be? I am at a real loss with all the vacuum stuff. The truck runs the same when I unplug and plug the hose that goes to the distributor. Any other suggestions of things to check? Thanks for your replies 89grand!

[mtn goat]

Red, did you try backing off the timing a little...2-3 degrees? Is your timing set with a light or by ear...hose to the distributer only works when engine is reved up on rpms so that sounds normal...start with the timing first

[Red's]

and by the way, it definitely isn't one of the motors thats on the air cleaner housing? the one that kind of hangs off the housing is the one that is lose and not working properly... just in case this might be it.

[Red's]

btt