Metallic rattle...
Discussion
One for the engine experts...
Car is an '83 2.2 n/a. When accelerating steadily, or at cruise on a light throttle, or decelerating, around 2300 rpm there's a rattle from the engine. If I lie on the engine
and open the throttle I can persuade it to appear. As far as I can tell it's coming from the front of the engine. I was thinking timing belt tensioner bearing? Aux. shaft bearing? Piston slap? Small-end?
There doesn't seem to be any related vibration; in a few hundred miles it hasn't got any worse or any better. There's plenty of oil pressure, although I believe the car was stood for the best part of 2 years before I bought it. The temperature is a steady 90 degrees, give or take a degree or two.
If I accelerate harder it doesn't appear.
Any ideas?
Ian
Car is an '83 2.2 n/a. When accelerating steadily, or at cruise on a light throttle, or decelerating, around 2300 rpm there's a rattle from the engine. If I lie on the engine
and open the throttle I can persuade it to appear. As far as I can tell it's coming from the front of the engine. I was thinking timing belt tensioner bearing? Aux. shaft bearing? Piston slap? Small-end? There doesn't seem to be any related vibration; in a few hundred miles it hasn't got any worse or any better. There's plenty of oil pressure, although I believe the car was stood for the best part of 2 years before I bought it. The temperature is a steady 90 degrees, give or take a degree or two.
If I accelerate harder it doesn't appear.
Any ideas?
Ian
wedg1e said:
One for the engine experts...
Car is an '83 2.2 n/a. When accelerating steadily, or at cruise on a light throttle, or decelerating, around 2300 rpm there's a rattle from the engine. If I lie on the engine
There doesn't seem to be any related vibration; in a few hundred miles it hasn't got any worse or any better. There's plenty of oil pressure, although I believe the car was stood for the best part of 2 years before I bought it. The temperature is a steady 90 degrees, give or take a degree or two.
If I accelerate harder it doesn't appear.
Any ideas?
Ian
Can't remember if this applies to the Esprit, but on the Excel there is a belt guard on the lower run of the cambelt between the exhaust pulley and the crank.
This is made of bent sheet steel and is held in place by a couple of bolts. If this was to work loose, it would cause a rattle at certain RPM as you descibe.
Probably worth a look.
Cheers,
Paul.
AZ88Turbo said:
Check the tension on your timing belt; it could be slapping against the top of the vacuum pump, I had that happen once.
It's hard to tell without hearing it but if it is the belt DON'T drive it until you have tightened it up.
Mark - 88 Turbo
He doesn't have a vacuum pump. It's an 83 NA
Paul.
Hi,
If you're certain it the front of the engine, it could be a variety of things such as alternator bearings, timing belt tensioner (as you've mentioned), A/C compressor if you have it or the waterpump bearing. Only a race bearing on the Aux. shaft, so unlikely that's it. There is no belt guard as suggested on your car. These are the easiest.
Worst case, you may have a #1 or #2 Main or Conrod bearing going, Camshaft issues (again these are race bearings, but if the car sat 2 years, the race(s) may have corroded badly. Hard to tell from the noise you describe, but a very remote possibility is that you have a cracked Bucket Tappet (or Cam Follower in Lotus parlance), these can make some weird noises.
A remote diagnosis is difficult at best, but if I had to guess, in decending order, I would look at the waterpump, timing tensioner, alternator, A/C compressor and clutch. These are the most likely culprits. Happy Motoring! ...Jim'85TE
If you're certain it the front of the engine, it could be a variety of things such as alternator bearings, timing belt tensioner (as you've mentioned), A/C compressor if you have it or the waterpump bearing. Only a race bearing on the Aux. shaft, so unlikely that's it. There is no belt guard as suggested on your car. These are the easiest.
Worst case, you may have a #1 or #2 Main or Conrod bearing going, Camshaft issues (again these are race bearings, but if the car sat 2 years, the race(s) may have corroded badly. Hard to tell from the noise you describe, but a very remote possibility is that you have a cracked Bucket Tappet (or Cam Follower in Lotus parlance), these can make some weird noises.
A remote diagnosis is difficult at best, but if I had to guess, in decending order, I would look at the waterpump, timing tensioner, alternator, A/C compressor and clutch. These are the most likely culprits. Happy Motoring! ...Jim'85TE
Another thing you can check is the front crank pulley bolt. When some clot (me!) last re built the engine, I managed to put the tappered washer in the wrong way round which ment the pulley was slightly loose. This made a light metalic rattle that was a arse to find as it sounded like the water pump was making the noise.
So it may be worth while checking that it is tight.
The only other thing you mention is the fact that you only get the noise when you lean on the engine. You could jack up the car and see if anything under the car is loose which may be rubbing on the alternator belt.
Just an idea.......
So it may be worth while checking that it is tight.
The only other thing you mention is the fact that you only get the noise when you lean on the engine. You could jack up the car and see if anything under the car is loose which may be rubbing on the alternator belt.
Just an idea.......
Cheers fellas:
Hilly, I didn't explain myself very well.. what I meant to say was that in pursuit of the noise, I climbed into the engine bay with the engine running, and I found the rattle seemed louder when I leaned towards the front of the motor! It rather sounds more like it's outside the crankcase, though you know what funny things engine noises can be.
I was vaguely planning on hoisting the engine out to do the cambelt, cam oil seals etc. so I may well trip over the problem then.
As the cambelt has oil on it I haven't been too enthusiastic with the throttle... about 4000 rpm max, hence the revs tend to build up slowly and the noise is evident. If I floored it everywhere I probably wouldn't have spotted it!
Ian
Hilly, I didn't explain myself very well.. what I meant to say was that in pursuit of the noise, I climbed into the engine bay with the engine running, and I found the rattle seemed louder when I leaned towards the front of the motor! It rather sounds more like it's outside the crankcase, though you know what funny things engine noises can be.
I was vaguely planning on hoisting the engine out to do the cambelt, cam oil seals etc. so I may well trip over the problem then.
As the cambelt has oil on it I haven't been too enthusiastic with the throttle... about 4000 rpm max, hence the revs tend to build up slowly and the noise is evident. If I floored it everywhere I probably wouldn't have spotted it!
Ian
B16 RFF said:
One for the engine experts...
Car is an '83 2.2 n/a. When accelerating steadily, or at cruise on a light throttle, or decelerating, around 2300 rpm there's a rattle from the engine. If I lie on the engine
There doesn't seem to be any related vibration; in a few hundred miles it hasn't got any worse or any better. There's plenty of oil pressure, although I believe the car was stood for the best part of 2 years before I bought it. The temperature is a steady 90 degrees, give or take a degree or two.
If I accelerate harder it doesn't appear.
Any ideas?
Ian
Can't remember if this applies to the Esprit, but on the Excel there is a belt guard on the lower run of the cambelt between the exhaust pulley and the crank.
This is made of bent sheet steel and is held in place by a couple of bolts. If this was to work loose, it would cause a rattle at certain RPM as you descibe.
Probably worth a look.
Cheers,
Paul.
Just checked a contemporary Esprit brochure that I have. There is a nice photo of the engine, which shows the belt guard I was refering to is not fitted.
Back to the drawing board.....
I have found on other vehicles that with rattle noises such as this, what I do is take something like a 1/2" drive extension or large screwdriver and just start pushing on non-moving things while the rattle is making noise. When you push on something and the rattle stops, you found it. Do be careful around the open belts, etc. Check heat shields, which are notorious for causing rattles in other vehicles.
Dr.Hess
Dr.Hess
Dr.Hess said:
I have found on other vehicles that with rattle noises such as this, what I do is take something like a 1/2" drive extension or large screwdriver and just start pushing on non-moving things while the rattle is making noise. When you push on something and the rattle stops, you found it. Do be careful around the open belts, etc. Check heat shields, which are notorious for causing rattles in other vehicles.
Dr.Hess
Yes, that's often the case. The only heat shield I can think of in this case is fitted to the nearside engine mount.
Also if you use a length of heater hose as a 'sounding tube' instead of a large screwdriver, you can listen to water pump, alternator etc whilst they are rotating. You only have to put the end of the tube close to the object being scrutinised, instead of making physical contact.
Paul.
>> Edited by B16 RFF on Thursday 17th June 16:35
Ian
I would certainly replace the timing belt sooner than later as you don't want to consider the mess if it breaks.......... It is more than do-able without taking the engine out.
In fact my belt is off right now to replace the front crank oil seal for the third time as it keeps on leaking. The service manual says you a need tool to fit the seal, I thought it just helped get the seal on, I didn't realise that it is used to centre the seal until after fitting a second new one and it still leaked. I had to make up a centering tool on the lathe as no one seams to have one. This could be why your timing belt is covered in oil.
Andy
I would certainly replace the timing belt sooner than later as you don't want to consider the mess if it breaks.......... It is more than do-able without taking the engine out.
In fact my belt is off right now to replace the front crank oil seal for the third time as it keeps on leaking. The service manual says you a need tool to fit the seal, I thought it just helped get the seal on, I didn't realise that it is used to centre the seal until after fitting a second new one and it still leaked. I had to make up a centering tool on the lathe as no one seams to have one. This could be why your timing belt is covered in oil.
Andy
hilly said:
Ian
I would certainly replace the timing belt sooner than later as you don't want to consider the mess if it breaks.......... It is more than do-able without taking the engine out.
In fact my belt is off right now to replace the front crank oil seal for the third time as it keeps on leaking. The service manual says you a need tool to fit the seal, I thought it just helped get the seal on, I didn't realise that it is used to centre the seal until after fitting a second new one and it still leaked. I had to make up a centering tool on the lathe as no one seams to have one. This could be why your timing belt is covered in oil.
Andy
Hmmm... how does that work then? Is the seal in a movable housing? I've had a look but can't tell where the leak is coming from, so I figured cams or crank as a start. For the amount of work involved in whipping the engine out, I thought I may as well do it; I can then check whether things like the plastic spacer on the gearbox input that I read so much about is intact; drop the sump and check the bearings, clean everything up, coat of paint where necessary etc etc. The cambelt will then be a doddle.
No point in having the facilities and not using them
My mate has just lent me the manual from his '75 Elite; at least I have a starting point on the engine details!
Ian
wedg1e said:
hilly said:
Ian
I would certainly replace the timing belt sooner than later as you don't want to consider the mess if it breaks.......... It is more than do-able without taking the engine out.
In fact my belt is off right now to replace the front crank oil seal for the third time as it keeps on leaking. The service manual says you a need tool to fit the seal, I thought it just helped get the seal on, I didn't realise that it is used to centre the seal until after fitting a second new one and it still leaked. I had to make up a centering tool on the lathe as no one seams to have one. This could be why your timing belt is covered in oil.
Andy
Hmmm... how does that work then? Is the seal in a movable housing? I've had a look but can't tell where the leak is coming from, so I figured cams or crank as a start. For the amount of work involved in whipping the engine out, I thought I may as well do it; I can then check whether things like the plastic spacer on the gearbox input that I read so much about is intact; drop the sump and check the bearings, clean everything up, coat of paint where necessary etc etc. The cambelt will then be a doddle.
No point in having the facilities and not using them
My mate has just lent me the manual from his '75 Elite; at least I have a starting point on the engine details!
Ian
Just remembered, there is a plastic gasket that fits between the oil pump housing and the auxilary housing, just above the oil filter and on the drive train for the distributor. These often leak.
Paul.
>> Edited by B16 RFF on Saturday 19th June 13:43
My late father was a doctor.
I now use his stethoscope for tracing weird knocks and rattles on my cars.
It is particularly good with air leaks, and I once managed to track down a tiny intermittent leak from the inlet manifold gasket of an old Renault.
Be warned that it is quite easy to damage your hearing using such a sensitive device near a running engine...
Pat.
I now use his stethoscope for tracing weird knocks and rattles on my cars.
It is particularly good with air leaks, and I once managed to track down a tiny intermittent leak from the inlet manifold gasket of an old Renault.
Be warned that it is quite easy to damage your hearing using such a sensitive device near a running engine...
Pat.
Ian
You are right, I would take the engine out as well, access to the engine bits is much, much easier with it out.
The front and rear crank seals aren't on a moveable housing but, are fixed to the block with M6 bolts and the holes in the housing are 7mm to allow adjustment to centre the seal. 1mm of movement doesn't sound like much but get it wrong and it will slowly drip oil all over your drive like mine did twice. The rear seal isn't too bad as it is much bigger and self centres (although Lotus do make a centering tool) but the front seal really needs the tool. I can send you a drawing of the tool I made up or I could even bung it in the post for you to borrow when you get round to whipping your engine out.
Andy
You are right, I would take the engine out as well, access to the engine bits is much, much easier with it out.
The front and rear crank seals aren't on a moveable housing but, are fixed to the block with M6 bolts and the holes in the housing are 7mm to allow adjustment to centre the seal. 1mm of movement doesn't sound like much but get it wrong and it will slowly drip oil all over your drive like mine did twice. The rear seal isn't too bad as it is much bigger and self centres (although Lotus do make a centering tool) but the front seal really needs the tool. I can send you a drawing of the tool I made up or I could even bung it in the post for you to borrow when you get round to whipping your engine out.
Andy
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