MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Jon S on October 23, 2018, 21:08

Title: Oil leak and misfire
Post by: Jon S on October 23, 2018, 21:08
Hello. The mr2 developed a misfire but got me home ok. When I had a look there seemed to be an oil leak around the right side of the engine around the head gasket level but also a lot around the timing belt tensioner. The code reader says I have a misfire on cylinder 2. So I'm hoping these things aren't linked and it's just a dodgey coil pack and a leaky tensioner gasket but I'm worried it could be the head gasket ( it did overheat 6 months ago when my auxiliary drive belt snapped but that's another story!) so what's the best way to diagnose my problem? And what do more experienced owners think the chances are it's HG?
Thanks for any hints
Jon
Title: Re: Oil leak and misfire
Post by: K T M Rider on October 23, 2018, 21:33
HG is I believe practically unheard of.

the following should help with diagnosis:

https://www.mr2roc.org/forum/index.php?topic=55930.msg645557#msg645557
Title: Re: Oil leak and misfire
Post by: Ardent on October 23, 2018, 22:28
+1 to that
Title: Re: Oil leak and misfire
Post by: mrzwei on October 23, 2018, 23:21
Swap a coil pack over to see if the misfire code moves, if not then could be an injector issue or a spark plug issue so if you can, swap one too. (First call is to pull the plugs and look for a difference on plug 2).
If all else fails then a compression test will maybe eliminate a head gasket. (White smoke and coolant loss would follow if this was serious). Beaten to it by KTM really ;D
Title: Re: Oil leak and misfire
Post by: Ardent on October 24, 2018, 00:06
With a nod to the other posters.

I would be inclined to put a failed head gasket very much to the bottom of the list.

You will find a failed head gasket failure next to hens teeth and rocking horse poo.
Title: Re: Oil leak and misfire
Post by: Jon S on October 24, 2018, 08:39
Heh heh! I'll check the plug first as this seems like a cheap and sensible move. Thanks for the advice I'll let you know the outcome (though may be awhile before I get round to it so don't hold your breath!
Title: Re: Oil leak and misfire
Post by: krazysteve on October 24, 2018, 20:13
Pull coil packs and check for oil leaking on rocker cover inner gasket around plug holes,not un common to cause a misfire.
Title: Re: Oil leak and misfire
Post by: Jon S on November 12, 2018, 20:54
Just an update. I replaced one of the coil packs and this sorted the misfire and I think the oil leak was from the timing chain tensioner so I've replaced this. I'm hoping this has fixed it! Thanks for all the opinions
Jon