Poly Engine Mounts. VIBRATIONS!!!!!

I’ve recently had my engine rebuilt, and I decided to go for Polyurethane Engine mounts.

Now I’ve heard these can cause abit of rattle which I didn’t mind the idea of...... until I took the car off the jack stands and let it idle. My god I’ve never seen anything like it. My wings are vibrating, my radiator shroud keeps wanting to come off, my indicator lights are all over the place.

Is there any way that I could do anything to stop these over the top vibrations?
Maybe I’ve done the mounts up too tight, or not tight enough?

Any suggestions would be appreciated. I may have to go for different mounts, I’ve heard BMW E34 mounts are a cheaper alternative to stock rubber mounts

Could always try nismo/new Nissan mounts or hardrace items.

What mounts do you have?

I had some poly mounts which were just insane.... Swapped them for a softer poly and they are much better.

If you have the simple ones which are a bit of poly and a bolt through the middle they do vary a lot depending how much you tighten them. Might be worth loosing them off a little, make sure you have some form of lock nut and check them regularly though!

Definitely sounds wrong. I had Apex Poly mounts and they didn't exhibit any of those behaviours. Popular mounts available from GKTech for pennies, or the real deal still sold by Nismo.

Check clearance to the cross member, I had some some poly mounts that were evidently manufactured incorrectly and the engine sat too low and was contacting the cross member. The vibration was insane just as you described.

I shall have a look at them and see what the issue could be. They were eBay ones, but I’d have thought that if it is made of polyurethane that it should be similar to the branded ones. They arnt just a piece of poly, they have two metal plates either side of the bush. My engine does sit quite low to be honest, If I wanted to take the bottom sump off I would need to jack the engine up. I shall try loosening them off a little. My rear view mirror can’t even stay in one position lol! It has a mind of its own

i had the exact same experience with the japspeed ones. i swapped them out for hardrace uprated rubber ones and its been perfect ever since, still use the poly gearbox mount though

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Originally Posted by lewi565

They were eBay ones, but I’d have thought that if it is made of polyurethane that it should be similar to the branded ones.

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Polyurethane is a material category, there are many varied blends and qualities.