Engine noises (NOT GOOD)

ga.spyder · Post by **ga.spyder** » Thu Nov 22, 2007 9:13 am

I have an 82 fi Spider,my pride and joy, that I have owned since May. The motor has always run great no noises ,good performance.I had a tranny problem ,which I had repaired (rebuilt) a couple of weeks ago. The engine has developed a high pitched whirring type of noise.It sounds almost like a belt slipping.I was sure it was clutch or tranny related.I took it back to my mech.,who was highly reccomended,30 years exp.,and only works on Fiats.He removed tranny,clutch ,etc. and bolted up a bellhousing w/ a starter and ran motor. Still there.We ran it w/ belts off.Still there.He has no idea what is making noise but feels its coming from bottom ,rear of motor.When the motor warms up,the noise goes away!! I am extremely confused and depressed.Any ideas or feedback is welcome!Is a teardown in order?With the Holidays and a weak housing market ,I cant warrant spending big bucks on a rebuild. Craig

ventura ace · Post by **ventura ace** » Thu Nov 22, 2007 9:49 am

One of the rear cranshaft bearings, maybe?? You can get the oil pan off to have a look see, with the engine still in the car, though it is not easy. If a bearing is messed up, the crankshaft journal may be scratched up, so you'd need to pull the engine to repair properly.

How's the engine oil level and oil pressure?

Alvon

ga.spyder · Post by **ga.spyder** » Thu Nov 22, 2007 11:26 am

hey Alvon, the oil pressure and level are fine. The oddest part is that as engine warms up ,the noise subsides.I am going to dump oil tomorrow ,and check for metal. Do you think there is something that could have been done during tranny work to damage crank or bearings,or just an ugly coincedence?

So Cal Mark · Post by **So Cal Mark** » Thu Nov 22, 2007 12:46 pm

there really isn't any tranny work that could affect the main bearings. Unless the flywheel was removed and is now contacting the steel plate that separates the engine and tranny.
Has any other work been done? I've heard timing belts make a noise like that if they're too tight

ga.spyder · Post by **ga.spyder** » Thu Nov 22, 2007 12:56 pm

The flywheel was removed ,resurfaced ,and reinstalled as I had clutch pack replaced w/ other work. We were sure it was tensioner bearing on the timing belt ,so my mech. relaced it w/ new belt and tensioner(charged me parts only). The noise remains! He also bolted a bellhousing w/ a starter to run w/o clutch etc..Noise is in motor.

racydave · Post by **racydave** » Thu Nov 22, 2007 7:14 pm

Its true, I learned from ffo last year, thanks Denise, If the timing belt is to tight, itll whirl!

mdrburchette · Post by **mdrburchette** » Fri Nov 23, 2007 7:23 am

You're welcome Dave. I'm glad people can learn from my mistakes!

ventura ace · Post by **ventura ace** » Fri Nov 23, 2007 9:37 am

Craig,
Do you hear anything strange when you turn the engine over by hand when cold (if you pull the spark plugs out, it should turn over fairly easy)? If so this might help you pinpoint the type of sound and more precisely where it is coming from. Since the tranny is out of the way, you could pull off the lower rear seal plate to explore further (take the bell housing off again, of course).

I wouldn't think that pulling the tranny in and out would have affected the engine. If the weight of the tranny was not supported well, could this have bent the end of the crankshaft while trying to pull the tranny in or out? I wouldn't think so, but I'm just reaching for straws here. Were the 2 locating hollow dowels in place between the bell housing and engine block (surrounding the 2 lower bolts)? If not, then I suppose that would create a scenario where the crankshaft could see a lot of bending force when the 4 bell housing bolts are removed. Even with the locating dowels in place, when you pull the tranny backward and clear the dowels, the tranny input shaft is still probably slightly engaged into the crankshaft pilot bearing, so letting the tranny hang by its own weight wouldn't be advised.

When you figure it out, Craig, please let us know.

Alvon

ga.spyder · Post by **ga.spyder** » Fri Nov 23, 2007 11:34 am

Hey everyone. Thanks for your input. I changed the oil today ,and there was metal present in filter and sump.Not a huge amount,but more than just 'fuzzy' shavings. It sounds as if it is coming from bottom rear of motor. It is such an odd sound ,that I am going to try(electronically challenged) to post a video of engine running so others can hear it. It is so odd that it goes into a shop running silent ,and comes out w/ a strange noise!I know they didnt work on the motor,but I feel that something must have happened ,maybe bending the crank like Alvon speculated.It has definetly thrown a dark cloud over my Holidays. Craig ps Alvon ,the tranny is not out of the car ,so I really cant check the dowel ,etc.

So Cal Mark · Post by **So Cal Mark** » Fri Nov 23, 2007 3:23 pm

it would be impossible to bend the end of the crank-the rear main bearing is only about 1/2" from the back end of the crank. When crankshafts bend, they bend in-between the main saddles.
If you can see metal in the oil, that's pretty extreme. I wouldn't run the engine anymore without pulling the pan and inspecting the lower end. Very odd that the oil pressure is normal. Does it knock for a moment when first started?

ga.spyder · Post by **ga.spyder** » Fri Nov 23, 2007 3:59 pm

There is no knock when the motor starts,As a matter of fact,when it first starts it runs silent for 15-20 secs. before noise starts. Against my better judgement I drove it for 15 mins. today. When I got back into the driveway ,the motor is running perfect and purring like a kitten,Not even a HINT of the noise!!! What the #%&#!!!! It only seems to do it until I get some temp in the motor. My mech. put a elect. stethoscope all around the motor,and it sounded bad while making the noise. You cant find a sound at all ,once it subsides.This one has me stumped ,and him too.

racydave · Post by **racydave** » Fri Nov 23, 2007 7:10 pm

Most oil pumps have a pressure by-pass, usually seat, spring and ball? I also wonder if the sump has become partially clogged with old gasket material?? I like to use a open stethescope for external noises. And if the oil pan has been dented or abused, I would especially suspect this as the problem!!!

ga.spyder · Post by **ga.spyder** » Sat Nov 24, 2007 5:52 pm

Hi Dave,the oil pan has some pretty good dents. I have been driving it like that since I bought it. It has always had good oil pressure and still does.The pump could have been damaged and gotten worse. I am going to pull the pan and visually inspect bottom end.This morning I started it to try and pinpoint noise and the motor was silent! I couldnt make it do it.This is the most frustrating thing I have dealt with ,and I have owned MG's!!!! Craig

So Cal Mark · Post by **So Cal Mark** » Sat Nov 24, 2007 6:13 pm

if the pan is dented, the pump pickup may be broken off. Some owners compensate by overfilling the sump by a quart. That works, until the pump sucks air from either hard cornering or low oil level. Then the bottom end goes away. and makes a load of scrap metal