Silicone on rocker cover gasket

[Traceyd254]

I am so sorry if this isn't the correct place to post and admin please delete if its not appropriate.

My 17 year old bought an MR2 mk2 in October last year. Its his absolute life, he loves it and its beautiful. In December his alternator failed as oil was leaking from his rocker cover gasket. The car went into the garage and they replaced the alternator and rocker cover gasket at a overinflated price in my opinion.

Fast forward to February and he noticed that the rocker cover gasket was leaking oil again. We contacted the garage and they couldn't fit it in until 12th March to have a look at it. 12th March came and he had covid so cancelled the garage and rearranged for this Thursday. He didint drive the car for 4 weeks due to circumstances and covid but when we drove the car last night it died and the AA helped up to the garage. I've spoken to the garage today and they are saying that it might not be covered under warranty as it might be another problem. My son is saying something about using silicone when installing the rocker cover and he doesn't think that the garage used any. Apparently its unusual but recommended by Toyota. Can someone please advise before I go with my mum head and try and stop him being ripped off. He's at college from 7am until 6pm so it's left to me who knows nothing about cars.

Many thanks in advance

[MR2DI4]

Okay for starters that gasket or rather 3 of them are quite expensive and yes I would put the right type of silicone in very small qty only in the gasket corners as the gasket jumps over the bumps for the Cams. The rest of the gasket has a raised rib when its new that provides a good seal, there is no silicone all round it from the factory.

The torque of the bolts that hold the cover down is quite critical and you need to take several passes of them before they are all correct. Overtime they generally need to be retorqued but we are talking years not immediately. Eventually the rubber goes hard and it starts leaking but your probably talking 10 years plus.

If the job was done correctly there should be no oil leaks in this area. It takes quite a bit of time to clean everything up and a lethal amount of dirt can go down the two holes in the cover into the gasket area that have the throttle body standoffs. This needs to be carefully removed so it doesn't fall into the engine.

Much of the oil on the alternator comes from people not using a funnel to put oil in the engine and pouring it all over the place. Unfortunately with the alternator on the back of the engine it gets oil blowback from any leaks, even from inside the cambelt cover if the likes of the oil pump oil seal has gone.

The alternator will not be cheap either and its horrible to replace on these cars with part of the exhaust needing to be removed first.

Someone in the UK can advise on what it should cost, I'm in NZ and I do all the work myself including rebuilding the alternator.

Did both of those jobs quite recently but the car is now sold.

[jimi]

There's no rockers on a MK2 engine, so no rocker cover, its normally referred to as the cam or valve cover. Toyota recommends the use of seal packing (silicon sealant) in certain places when refitting the cam cover. This is shown on page EM131 of the 3S-GE engine manual, a pdf copy of the manual can be downloaded from here https://www.mr2oc.co.uk/download-cats/d ... anual.html
Did the AA say why the car had died ?

[Traceyd254]

Thank you so much. The AA said that oil had leaked into the alternator from the rocker cover gasket :-)

[MR2DI4]

You will find that an alternator typically does about 160,000km and just dies anyway. Usually the brushes in it just wear out regardless. If you can catch it before it fries itself then a clean up, some new bearings, brushes and a new rectifier pack will see it go for another 160,000km.

[jimi]

If they replaced the valve cover gasket & alternator in December because leaking oil killed it and its failed again in 3 months with the same fault then there's something far wrong and they should certainly be repairing it under warranty. Might be worth talking to the C.A.B. if they are playing silly buggers.

[Traceyd254]

Thank you everyone, garage were fine, they replaced the rocker cover gasket again and the alternator under guarantee on Thursday but guess what it's leaking again today. Another trip to the garage tomorrow but not sure what the solution is as they obviously can't fix it or fit it correctly :-(

[jimi]

Here's the relevent page from the BGB, you can always download and print it or put it on a phone to show them, make sure they are doing it correctly ?

EM131..jpg (52.94 KiB) Viewed 63 times

[TonyleFrog]

@ jimi - could your post on this thread be relevant?
https://www.mr2oc.co.uk/forum/41/160258 ... n#p1691604
The other question is whether the garage is using the correct method of tightening the bolts (per your BGB extract). If not, it can distort the gasket. The sealant won't overcome that.

[jimi]

Quite possibly, be worth while checking the part number of the gasket the garage has used, they may have the wrong gasket. I'm not familiar enough with the MK2 gaskets to say what the differences are. If the OP could post the VIN (or PM it to me) I can easily check which one (part number) should be used.
Good thinking Tony