Lotus Esprit S1, vibration on steering wheel

[elan71]

I'm the lucky owner of a Lotus Esprit S1. I have the car since 2 years. From the beginning I always have strong vibration on the steering wheel during acceleration the car. It's irrelevant which speed I drive, it's always during acceleration. I had balancing the wheels and I rebuild the steering also because of some slackness. Now the vibration is stronger. So this was not the problem, because the vibrations are not at the same speed. It is not a kind of out of balance

Edited December 12, 2007 by USAndretti42
Made the text bigger

[andydclements]

I'd suggest looking at the engine mounts, under acceleration the engine will be trying to move, and the mounts should hold it in position, quite firmly. If they're not doing this, the engine will move and you can get vibration throught he chassis and road wheels.Andy

Edited December 11, 2007 by andydclements

[iainskea]

Is it a clutch judder? - is it only up-hill (incline)?

Neat fault, and will be interesting to see what it is.

Iain

[elan71]

Thanks for first answers.

Engine mountings, could be. I have a set of new mountings. Mounting near the exhaust it is always critical.

I don't think its the clutch. I have the problem also on normal street. We do also have normal streets, not just mountains with high alpine pass here in Switzerland, but it makes a lot of fun to drive over a alpine pass with an Esprit.

I also think about new bushes (polys) for front suspension?

[iainskea]

Gotta be back-end stuff (on acceleration / load). Maybe the main drive universal joints(?).

Iain

[peteyg]

Hi Daniel,

I had this problem and the cause was the engine mounts. I discovered this after I rebuilt the front suspention and changed the steering box!!

Pete

[espritmania]

Hi,Daniel if you take your engine cover off then and see if the engine lifts up when you put your foot down also see if your gear stick moves slightly back when you move off from stand still.IF they do then you will find that the engine mountings have come appart.WHat you need to do is replace them but you need to make a heat shield for the exhaust side if you do this they will hopefully never split again and hopefully solve your vibration problem.Thanks Paul G.

[Tony K]

I agree with all of the above -- engine mounts. Also, I want to add that you should install the engine stabilizer rod. This was a factory upgrade -- I think late S2s had it, but it was added to a lot of S1s later in life. It is a rod that goes from the frame to the bellhousing to reduce the lift and pull of the engine under acceleration and deceleration.

- t

[elan71]

Thanks for your help.

OK, I will check my engine mounts and replace them.

I know, I have a heat shield, it looks like and I think it's not very good. It's just a piece of head resistive foil. Have anyone a picture of his solution who is more professional?

Tony

A engine stabilizer rod sounds interesting and make sense. Have you a picture of this solution? Or a part number and where can I order this?

Have anyone also installed the engine stabilizer rod?

Car is at his winter place at the moment, I have to wait until snow is gone.

I will post my results.

[iainskea]

Daniel, SJ Sportscars (UK) has a kit for a good price here:

http://www.sjsportscars.co.uk/partsandacce...amp;Type2_ID=73

I made mine out of a can of coke ...mind you, you did say professional, so I would go with SJs.

Iain

[Tony K]

Thanks for your help.

OK, I will check my engine mounts and replace them.

I know, I have a heat shield, it looks like and I think it's not very good. It's just a piece of head resistive foil. Have anyone a picture of his solution who is more professional?

Tony

A engine stabilizer rod sounds interesting and make sense. Have you a picture of this solution? Or a part number and where can I order this?

Have anyone also installed the engine stabilizer rod?

Car is at his winter place at the moment, I have to wait until snow is gone.

I will post my results.

In addition to my standard heat shield, on my red S1 I also wrapped the motor mount in insulating tape and then foil on the outside with wire to secure it. The mount has lasted 7k miles so far, and that's with no stabilizer bar. My old record was about 6,300 miles. I don't know whether my added insulation helped, or if I am just lucky.

As for the stabilizer bar, most or all of the usual vendors in the States will have it. (By the way, where are you?) Here is a pic of what it looks like, although this one is a little beefed up. It is the rod and plate attached to the bellhousing; the threaded rod whose end is just visible at the bottom goes back and attaches to the frame:

Edited December 23, 2007 by Tony K

[iainskea]

...err Tony,

My S2 907 doesn't have this stabaliser rod - is it supposed to?

Iain

[elan71]

@ Iain

Thank you for the link to SJ Sportscars. I know this company for good service and quality. I'm in contact with Steve from SJ Sportscars and he try to help me too

@ Tony

Thank you for the picture of your engine stabilizer. I never have seen something like that. But it looks efficient.

It looks like in the UK this up-grade is not popular. Can you give me any usual vendors in the States who is willing to deliver to me?

I had brought my car to my home last weekend.

I had also monitoring my engine during a drive, unfortunately I can not see something exceeding. All vibrations on the engine look normal. The engine does not lift up during acceleration.

Also the rubber on my mountings looks good. No cracks or broken or similar as you can see on the pictures.

I have no idea where these vibrations on the steering wheel are coming from. I feel the vibration only on my steering. The rest of the car is smooth and still and I don't feel any vibration on passenger side, for example.

I also thought about to overhaul the whole front suspension with poly. But the front suspension looks also very good. All rubbers are in good condition.

Maybe someone have another good idea, or a test procedure to find the failure?

[Tony K]

Iain, I've always been told that Lotus introduced the stabilizer during the S2 run and that late S2s that have it, but I could be mistaken.

I believe Lotus issued a technical service bulletin for this when they introduced it to retrofit it to earlier cars. I may have a copy of it.

Daniel, If SJ doesn't have it, I would first check with R.D. Enterprises -- www.rdent.com

Also, try JAE -- www.jaeparts.com

The last time I checked, which was several years ago, the kit was around $100 USD. But it may be double now because of the falling dollar.

If you want to try to build it yourself, Kiyoshi Hamai from the Golden Gate Lotus Club (San Francisco area) drew up plans with how you could fabricate one yourself -- see here: http://www.gglotus.org/ggtech/esprits1-eng...le/enginest.htm (note this is from 1983!) I believe he is still active in the Lotus club, so you could probably contact him or someone else in the club for a better version of the illustration if you wanted to do it yourself.

My blue S1 is the only one of the three that has it. I think it is great. The car feels a lot more "solid"with it properly adjusted.

If your vibration turns out to not be motor mount related, I would also look at the U-joints, the output shaft bearings in the transaxle, and the suspension bushings for the lower links and trailing arm. The lower link bushings appear to receive the most stress and get squished the most, and the left side trailing arm bushing takes a lot of heat from the manifold just like the motor mount.

I hope this helps!

- Tony

P.S. -- LET'S SEE SOME PICTURES OF YOUR CAR!!!!!

[USAndretti42]

Going back to Iain's question, my S2 has an air injection pump. The stabilizer goes from the bracket for this to the chassis. The air pump sort of replaces the rod in Tony's picture. I wonder if it's a US only thing.

[elan71]

@ Tony

Thank for your answer.

I think I will try the engine stabilizer.

Positive is, I knew the hole history from the car since 1983.

The history shows me that the suspension bushing for the trailing arm was replaced twice and U-joins are brand new. But this could be the problem.

I'm wondering why you think the vibrations coming from the rear suspension.

The problem is during acceleration the car. The weightiness will go to the back of the car and the front suspension will be unloaded. Exactly at this time I feel to strong vibrations. Should I better search the problem at the front suspension?

Daniel

PS: OK, Yes, I will make some pictures soon and will show my car here at the Esprit forum. J

[elan71]

Hi

here my promised pictures at the newbie section

http://www.lotusespritforum.com/forums/ind...hp?showforum=15

Daniel

[jonroberts]

A friend of mine had a vibration which turned out to be a tyre with a flat spot on it. The flat spot came from the car sitting in the same spot and not moving for a long time (like a lot of Esprit's do !). When examined closely, although the tyre was in balance, it was bad. Replacing the tyre cured the vibration in his case.