Dry Bearing Noise And A Miss-fire

[rm0rgan]

Morning Folks,

 

Two things that are causing me to be up at 5.30am typing away on here!

 

1) I have developed a miss-fire that is getting gradually worse. At first it only happened at low revs and when the car had warmed up - when it was cold it seemed ok. Today it is present when warm and under any hard throttle load.

 

Could it be a spark plug breaking down or something more sinister? I am planning on changing the plugs anyhow as a way of ruling them out - Which plugs are best to buy (2001 S2 Elise 1.8 with Hurricane and Janspeed System)

 

2) This one is more concerning. I washed the car before going abroad for 3 weeks working and did nothing other than a usual wash and hose off with a pressure washer and then just dried it off and put it in the garage - Now, on coming back and starting the car up yesterday I have noticed that I have a 'dry bearing' type noise coming from around the alternator/bottom of the cambelt pully area (basically, its more noticable when you get your ear in the drivers side cooling vent!). I took it for a drive but it did not get any better. It sounds very much like a knackered thrust bearing might, but is not the clutch (in theat it does not dissapear when I depress the clutch)

 

Any ideas? I'm hoping it might be the bearing in the alternator so am planning on dropping the belt on the weekend to see if it goes away.

 

Any other things I should check/be aware of while trying to diagnose?

 

All help appreciated.

 

Cheers for now

 

Rob

[ant13375]

Hi Rob

 

One thing to look at with your misfire is your leads, i had the same concern and found this to be the cause

 

Ant

[Phil.S]

Best to change the plugs, leads, cap and arm all together seen as they're pretty cheap then it pretty much rules out the main ignition components.

[dobbo]

A couple of years ao we went on a 2 week holiday. Car was fine when we went, alternator was siezed when we got back. On removing it, the entire casing, in which the bearings are caged, was cracked and distorted.

 

It was very clear on that car as there was a horrible screeching noise followed by a big cloud of smoke from the alternator belt burning up.

 

It's possible that yours has a similar problem, but not in quite as serious a way, ie the cage is slightly distorted, enough to cause a bearing noise but not enough to sieze it.

 

We never worked out how it had happened as all was well before holiday and it was totally FUBARed when we got back.

[MikePMC]

First issue is most likely the cap, leads or arm (in that order) but probably a good idea to change the plugs at the same time. Give it a mini service!

 

Second issue, I'd agree fully that the alternator sounds like it's on the short journey to the bin, but check the tension of the belt first just in case.

 

Mike

[rm0rgan]

First issue is most likely the cap, leads or arm (in that order) but probably a good idea to change the plugs at the same time. Give it a mini service!

 

 

Appreciate the info - any recommendations on where to buy cap, leads or arm from?

 

Also, assuming it is the alternator, where is the best place to source one? does anone do recon/exchange units or is it best to buy new?

 

Any indicative costs also appreciated :-)

[dobbo]

Caps / leads / arm - standard Rover parts

 

Alternator - refurbs around £100 but not usually recommended. DON'T go to a Lotus dealer - again it's a standard Rover part.

Also, the lightweight ones are not recommended for road use - they're usually for race / track use where the revs are higher for the majority of the time.

At "normal" use, they often don't put out enough juice.

[fentuz]

I had the same issue last week regarding misfire... the inside of distributor cap for wet and I eventually broke down....

Change cap and rotor for £15...

[R.I.B.]

I had really bad miss fire happening a couple of weeks ago, turned out that the spark plug had got a bit of standing water sat around it and it wasn't functioning correctly.

It also was ok (ish) when cold.

Nice simple fix for what was a bit of a panic when it started happening.

Phil

[Guest father4justice]

check the tension of the belt first just in case.

 

Is there a recognised way of checking the alternator belt tension on an S1?

[dobbo]

The manual says "with moderate finger pressure, the belt should have 6mm one-way movement". I take that to mean you can push it in 6mm or pull it out 6mm. What "moderate finger pressure" means is another question.....

[Guest father4justice]

Cheers - I'll have a go at exerting "moderate finger pressure" then!

[MikePMC]

Cheers - I'll have a go at exerting "moderate finger pressure" then!

 

 

Not 100% on the Elise as the alternator is bigger slightly, but on the race Metro I generally see if the belt can be twisted more than 90 degrees. Generally 45 degrees is about right so it should be there or there abouts with the Elise.

 

Mike

[Guest father4justice]

Not 100% on the Elise as the alternator is bigger slightly, but on the race Metro I generally see if the belt can be twisted more than 90 degrees. Generally 45 degrees is about right so it should be there or there abouts with the Elise.

 

Mike

 

Thanks - that's how I usually check tension but I was hoping for something a bit more scentific.

[rm0rgan]

Sorted!

 

It was a failing coil so have replaced them along with a new set of plugs...

 

As for the bearing noise, I dropped the alternator belt off and the noise went so now know it's the alternator bearing that has gone dry. I'm going to get this replaced next week as I sadly i've got to sell her to make funds for my next toy...i'm going for an Exige!

 

Cheers for advice on this thread - all pointed in the right direction.

 

Rob