Give the IAC and the throttle body a good cleaning with some carb cleaner and see what happens...

 

1. As the engine temperature rises the noise begins but is not consistent.
Sometimes the sound seems like the timing chain slap. I driven the car now for about 1,000 miles with no increase in noise or consistency.

2. With the car in park and rev the engine with no load there is sometimes a grinding and/or clanking noise when the engine is warm. At about 2500rpm the noise goes away.

3. A/C (on or off) does not make a difference. This was my first concern thinking the a/c clutch bearings was the problem.

Thanks for the quick response. Joe.

 

might need to check the motor mounts (pop the hood and start the car. peek under the hood and watch the engine. hold the brake and shift to reverse then drive and back again and then into park). if the engine rocks an inch at all, you may have bum motor mounts.

and yeah, it could be something rattling in the cat that at the higher RPMs gets stuck in one place.

as for my MGM, I got some carb/throttle body cleaner and hosed it and the IAC out. there was a good layer of crud that washed out. had to get a rag and wipe off the heavy stuff at the point where the flapper closes. it's much cleaner now. we'll see how the warm starts go this week.

 

Before you get too worried have you tryed running the engine with the accessory belt removed just to be darn sure you don;t have something going on with say a power steering pump/alternator/water pump? Best bet would be to warm it up till the noise starts, shut if off, remove the belt, then start it for no more than a min or two to see if the noise is still there...

Without hearing the noise it's hard to say for sure but It very well could be somthing timing chain related.. Although the timing chains on these are relatively bullet proof till a quarter million miles the chain is tensioned hydraulically using the engine oil pressure...

If say your oil pressure was a bit low, the stp would thicken the oil up and gain some extra pressure.. The oil also gets thinner as it gets warmer causing a presure drop.. When the oil pressure would drop the tensioner wouldn;t put as much tenstion on the chain causing it to slap around in there...

More likely the cause would be a problem with the tensioner itself though.. It could be leaking pressure off, or have some gunk of some sort in it causing it not to pump up properly...

Older 4.0 explorers had a habit of lifters tapping due to gunk building up in them.. The trick we used to do at the dealer was replace one quart of oil with a quart of auto trans fluid.. The detergents in the atf would knock the crud loose and clean it out.. Sometimes it would take two oil changes, but it would usually cure them.. Possibly someting like this could work in your case if it is for sure a chain tensioner problem..


If your car has an oil pressure gauge it isn;t too terribly accurate. The gauge works on pressure ranges not actual pressure.. For example pressure from say 0-10 psi would make the gauge read in the low area.. 10psi - 50psi would be in the normal area. Anyting over 50 would be in the high area.. Best bet would be to verify your oil pressure with a mechanical gauge under the engine is making noise, and not making noise... If nothing else this could rule out major problems with the engine oiling...

 

Thanks maxfax3!

The timing chain may be the culprit. I drove the car 300 miles this weekend in south Texas. Coming home and driving this morning I did not hear the clanking noise. It could be the colder weather.

You suggest putting 1 quart of ATF fluid into the oil crankcase. I then let the engine idle for about 10 minutes. Then replace the oil. Is this correct?

Was using Mobil 1 pure synthetic a waste of money? It didn't seem to prevent this issue from happening.

Thanks again. Joe..

 

The 4.6L Mustangs had tensioner failure. Major issue! See link below.

http://mustangforums.com/forum/4-6-m...ing-noise.html

 

Some will put it and run it for 10 mins before changing the oil.. There are some that will simply replace a quart of oil with ATF at an oil change and run it till the next oil change.. I guess it would depend on how hard you run it.. If it is something that is run hard/tows that kinda thing I would probably opt to just do a 10 min flush...

There is also stuff out there called Seafoam.. They mention right on the instructions that you can run 1/3 of a can with your oil... It can also be run as a fuel system cleaner too.. Adn that stuff does clean!!!

What weight of Mobil 1 are you running? I run the same thing in my 96 MGM.. I'm using 10w30 oppsed to the 5w30 it recomends... But then again I push it about 10K between oil changes... Still comes out pretty clean...

 

I've been using 10-30 Mobil 1 extended performance for the life of the car. Fram 7,500 mile oil filter. Changed oil every 5,000 miles.

 

just an update on my 88 MGM, cleaning the throttle body out sorted the starting issues. It also sorted the air issues in general it seems. Runs much better now.

 

Good deal.. Amazing what carb cleaner and duct tape can remedy!!!


Joe: Finally got a chance to read that link.. Mustang GT would be the SOHC engine similar to yours... I guess I got outta the dealer before these started letting loose.. Looks like this problem really makes itself known on about '98 models and up...Most of what I see though my shop now are all about '94 - '97 cars.. Couple of them are pushing 300K with no other problems than smoke and oil consumption (vavle seals mostly I suspect).. Figures, they get something decent and have to screw it up...

Pending on how handy you are getting to the timing chaings isn;t too terribly hideous.... Yank the accessories, valve covers, and timing cover... The power steering pump is a bit tricky.. Gotta pull the pulley to get the one bolt out of there.... Getting everything timed isn;t as scarey as it may look.. Now pulling a head on one of these... That is not fun!..