what is this weird engine noise?

[88 E5PR1T]

youtube video: http://www.youtube.c...h?v=zyP784xMTzY

Tuesday, my engine started to make this weird noise. It occurs around 1200-1400 rpm (where the car idles right now). It's loudest right where the bellhousing meets the transmission (shown in video).

Ive owned the car for about 2 weeks, and have gone ~400 miles with it so far.

It does not change pitch if the clutch if pushed in, and it does not matter if im standing still or rolling along at 1200-1400rpm in first gear. Its there upon startup and when you turn the key off as well, and varies frequency with engine speed.

it seems to go away around 1600+ rpm, but im not sure if it completely goes away or just goes to a frequency thats unhearable.

flywheel? pressure plate? we eliminated the clutch, transmission, and input shaft because with the clutch pedal down, they should not be rotating and wouldnt make the noise. not the output shafts obviously because the car is stationary.

Any input would be appreciated

[USAndretti42]

My first thought was release bearing until I listened to the video. Not whining but knocking. I foresee you having to split the engine and transmission to have a look in the bellhousing and to check your pilot bearing.

[molemot]

Agree about the pilot bearing...could also be crankshaft endfloat? Have you had a look in the hole at the top of the bellhousing, where the timing marks are visible, to see if you can detect any flywheel movement?

[nodemgr]

maybe the vacuum pump intake tube fell off? or how about a loose tensioner for the vacuum pump causing the pump to wobble?

[stevem]

My Esprit had the same noise when I first got it. It was the vacuum pump exhaust outlet, which is a black rubber hose about 1" in diameter that ends up at the side of the gearbox just behind the bell housing. It's easy to see from underneath, and if you stick your finger on the end of it, you should feel air blowing out and hear the sound change. Listening from the wheel arch it's easy to mistake the sound as being from the gearbox.

I made a simple 'silencer; for mine using a piece of tube with some gauze inside it stuck to the end, to muffle the sound but still let the air out. I also found it was louder than it should be due to a vac pipe being off under the dashboard which feeds the vent flaps. Re-attaching that pipe made it a lot quiter and fixed the heater problems too. If a vac pipe is off, the pump sucks in air and expels it making that knock/popping noise.

It's worth having a look, it could be $5 to fix instead of a gearbox rebuild that won't fix the noise.

Here's a photo of where mine is located, the arrow shows the end of it where i fitted my home-made muffler. Looking at you video, the camers mic would have been almost next to it when you took the shots.

Good Luck,I hope it turns out to be as simple to fix yours.

Edited May 2, 2010 by stevem

[trackmagic]

Start with the vacuum pump.

Best,

Jeff

[88 E5PR1T]

stevem, youre a genius and a lifesaver. i was just about to split the motor and transmission apart to investigate the bellhousing.

Great info guys, thanks. This forum is invaluable.

[Dad of Member]

Thanks Stevem. Rob is right. You saved us a lot of work. (un-necessary work) These forums are really a great tool. I belong to two other forums (car and watchtalk) and have found them GREAT !

As Rob's dad, I thank you.

Bob

[stevem]

No worries, I'm glad you found the problem. I suspect if the vac pump exhaust was making that noise though that you may have a vac pipe off somewhere in the car that will need finding. Check that all your heater/demister controls are working and that the flaps move properly when you move the controls. The vac pipes are thin black plastic tubes connected together with rubber joining bits ( some of them are t-pieces ) and easily get dislodged. I had a bloke pull from a transport company pull on one of mine mine thinking it was the front hatch release cable when he stuck his hand under the dash.

I am sure once you get all the little niggly bits fixed, your Esprit will be a lot of fun and you'll find it quite easy to work on the usual service items.

At a dodgy workshop, that might have cost you over a $1000 for a "transmission fix" so remember - always check the easy things first.

Good Luck.

Edited May 3, 2010 by stevem

[88 E5PR1T]

We swapped out the vacuum pump with NAPA part number 64-1006... Perfect.

http://www.napaonline.com/Search/Detail.aspx?R=NVP641006_0131266240

FYI to anyone who may need this info in the future: the NAPA 64-1006 does not have an exhaust port like the OE unit, so the 3ft exhaust hose can be removed from the car.

Thanks again.

Edited May 6, 2010 by 88 E5PR1T

[Simon350S]

Glad you got the old girl fixed up for cheapo prices!

Why not join as a full member, think how much it's saved you ready!

Ooh, you get acess to a downloadable parts manual as well which will help even more in the future!

[Kirk Adamson]

god . couldnt sleep last night . up all bloody night . spent most of yesterday under the car in bonnet etc etc . mates round.. ooooo that sounds bad crankshaft  . thrust bearings . get the engine out they cried .. looked on the forums this morning watched the youtube video.. thats the bloody noise i thought. depression lifted iam a happy man. now to find the pipe thats off. only thing ive done in last 5 days has been to take battery off to charge. replaced petrol tank breather hoses. smell of petrol now gone.. but cant think how a tubes come off in the cabin !!!

[Sparky]

If you've been at the breather hoses, then there's a good chance you've disturbed a vac hose under the side panel at the RH rear window.

[Kirk Adamson]

yep you were spot on exactly what you said found it pushed it back together brake warning lights went out noise stopped etc etc. cheers. kirk