Poly Engine Mounts

Discussion and technical advice for 84-89 AW10 & AW11 MR2. 3A-LU, 4A-GE, 4A-GZE.

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Jim-SR
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Re: Poly Engine Mounts

Post by Jim-SR »

LoSt GhoSt wrote:
classic mk1 wrote:Have you got a link for the ebay ones, i brought the 2s r us ones which i had to drill. Becarefull with these mounts if theyre too rigid they will crack the chassis due to transmitting too much load.


Yes guys, be careful there has been reports of the front engine mount tearing off of the chassis. Although, somebody on MR2OC said it was because the worned out side mounts were neglected and so it would cause the motor to slightly twist putting to much load on the front and back causing them to rip out.

I would suggest filling the side mounts just to be on the safe side. And if you guys have rust under there. I wouldn't put any stiffer mounts unless its been inspected to make sure its safe.


the front mount, and sometimes the rear, will rip off the chassis regardless if you stiffen it up. this is just a weak area of the chassis, Toyota got it wrong (shock horror!) and over time it fatigues. on the American forums they are several people that have had stock mounts rip away from the chassis, and most people that uprate them have had trouble at some point down the line.

the only way to prevent it (and its important that you PREVENT it. dont neglect it and then end up FIXING it later. its much easier to do the work now before youve done the damage) is to reinforce the chassis in this area. anyone changing mounts should get it done as a matter of course really. it only needs some simple welded reinforcement. once its been welded it wont be an issue. im going to do both front and rear mounting areas on mine before fitting solid poly mounts. then im going to urethane the side mounts.
IanClements
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Re: Poly Engine Mounts

Post by IanClements »

I've had mine on for a couple of years now without any problems. I used a bag of poly from RS recommend by Woodsport but had to drill holes in to take away the vibration.


Mine are still fine, haven't done huge mileage though.
Ben
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Re: Poly Engine Mounts

Post by Ben »

My Sikaflex'd ones are still going strong :D

I must have done at least 2-3k on them by now...
2001 BMW M5 (Bahnstormer) | 2004 RX8 231 (the Racecat) | 2001 Volvo V70 (Swedish eBay barge)

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1989 MR2 Mk1b T-bar | 1988 MR2 SC Super Edition
Kooga
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Re: Poly Engine Mounts

Post by Kooga »

Ben, did you completely fill them with sikaflex or did you drill them through as per the PU fix? Just wondering cos I've got 2 different cars on the drive needing mounts now, and that's plenty £££'s in Japanese....
Tiny
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Re: Poly Engine Mounts

Post by Tiny »

I sikaflexed mine mid week and there is a slight increase in vibration i have no 5th gear nod and the whole set up just feels so much better.

Do it. you wont regret it. :thumleft:
Ben
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Re: Poly Engine Mounts

Post by Ben »

Kooga wrote:Ben, did you completely fill them with sikaflex or did you drill them through as per the PU fix? Just wondering cos I've got 2 different cars on the drive needing mounts now, and that's plenty £££'s in Japanese....


I did drill the front, but after there was still a little engine flap evident. So, I did exactly the same with the old front mount but without drilling, and it's been good as gold ever since.

I actually did a little write-up HERE :thumleft:
2001 BMW M5 (Bahnstormer) | 2004 RX8 231 (the Racecat) | 2001 Volvo V70 (Swedish eBay barge)

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1989 MR2 Mk1b T-bar | 1988 MR2 SC Super Edition
Kooga
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Re: Poly Engine Mounts

Post by Kooga »

Top stuff, cheers mate, it is all clear now. Have you (or anyone) done the side mounts or is this deemed unneccessary?
PeteP
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Re: Poly Engine Mounts

Post by PeteP »

Worth BUMPing. In the complete absence of replacement bushes it seems this is a fairly critical bit of DIY knowledge.

How are the pioneers getting on?
Ben
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Re: Poly Engine Mounts

Post by Ben »

Mine lasted fine until I sold the car in January 2010. Must have done about 10k miles on them with no problems at all. The guy who bought it off me still has it as his track car, he's done another 15k miles including many track outings and a trip to the nurburgring - I believe he still has the DIY mounts fitted :thumleft:
2001 BMW M5 (Bahnstormer) | 2004 RX8 231 (the Racecat) | 2001 Volvo V70 (Swedish eBay barge)

Previous:
1989 MR2 Mk1b T-bar | 1988 MR2 SC Super Edition
PW@Woodsport
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Re: Poly Engine Mounts

Post by PW@Woodsport »

I don't think the 4a-ge has enough power to trouble the torque mount areas, on 3s-gte and V6 builds i reinforce the chassis areas where they bolt on, use the best quality bushes i can find (PU on the stock mounts is a bodge in my opinion) and i then fit a small shock absorber to the front torque mount, the result is an engine that sits where it's told, doesn't break anything and no excess chassis vibration (NVH)

As for bushes not being available, i offered front and rear torque mount inserts last year but nobody was interested.
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aw11rally
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Re: Poly Engine Mounts

Post by aw11rally »

PW@Woodsport wrote:I don't think the 4a-ge has enough power to trouble the torque mount areas, on 3s-gte and V6 builds i reinforce the chassis areas where they bolt on, use the best quality bushes i can find (PU on the stock mounts is a bodge in my opinion) and i then fit a small shock absorber.


I've had problems with 3 front torque mounts. One standard 4a-ge road car with poly mounts, one tuned 4a-ge with alloy inserts and one 3s-gte.

I'd say if you're going to change the engine bushes to anything other than standard then the front torque mount needs reinforcing.
PW@Woodsport
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Re: Poly Engine Mounts

Post by PW@Woodsport »

To be fair you are ragging the hooters off yours though :D
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stenky
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Re: Poly Engine Mounts

Post by stenky »

today, i am going to pour some flexane on them mounts to solid fill them. chasis looks good. the engine is underpowered so hopefully, no metal will be hurt just now :-k
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aw11rally
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Re: Poly Engine Mounts

Post by aw11rally »

PW@Woodsport wrote:To be fair you are ragging the hooters off yours though :D


I'll take that as a compliment :thumleft:

Mechanical sympathy is not something I am renowned for. But if I can break something in a few months then for someone looking for bulletproof reliability (arn't we all) my R&D is very useful. Even if it will take a normal human another 50k to suffer the same failure.
PW@Woodsport
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Re: Poly Engine Mounts

Post by PW@Woodsport »

Totally agree, but under those conditions the normal Mk1 owner would only need to change their torque mounts once in the cars life, and as such it should be done properly.

I guess i just don't agree with bodges when there's a proper way to do it.
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LimeyMk1
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Re: Poly Engine Mounts

Post by LimeyMk1 »

Paul what thickness steel do you use and do you have any piccies of the plating you put on the chassis rail? :thumleft: It's something I must do on my Mk1. :-k
PW@Woodsport
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Re: Poly Engine Mounts

Post by PW@Woodsport »

Hi Chris, I use 3 or 4mm plate over a 6" area on the front crossmember and a 40mm angle section on the rear, seems to beef those two areas up sufficiently.
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PeteP
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Re: Poly Engine Mounts

Post by PeteP »

I've only been a round for a couple of months so that would have been before my time,Paul. I don't suppose you still have anything available, do you?

Although mine aren't exactly shot and there's not much likelihood of my driving style causing the sudden onset of fatigue, there is a degree of slack as the power goes on and off - most noticeable in 5th but not exclusively. If I hold the gear stick forward (firmly, not hard) as I accelerate, the play is eliminated and the power feels smoother.


It's only my amateur impression that this is the mounts rather than a gearbox issue developing, but I'm sure you'll be able to put me right if I'm misinterpreting the evidence.

It's not something I feel compelled to do immediately (thankfully) but it's good to learn as much as possible when things like this are fresh in my mind. More urgent is the track rod issue I've created for myself - but that's another story.
LimeyMk1
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Re: Poly Engine Mounts

Post by LimeyMk1 »

PW@Woodsport wrote:Hi Chris, I use 3 or 4mm plate over a 6" area on the front crossmember and a 40mm angle section on the rear, seems to beef those two areas up sufficiently.


Coolio, cheers Paul. Do you make up a bracket for the damper? I've got a damper I bought at JAE a few years ago, just got to figure out where to stick it. :lol:
PW@Woodsport
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Re: Poly Engine Mounts

Post by PW@Woodsport »

I just make a bracket in situ for that, it normally just bolts onto the lower torque mount and an extended piece on the gearbox mount.
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