Misfire/Blowing Exhaust

<Archived> Even supercars have their flaws..
Madone
Posts: 25
Joined: Fri May 30, 2008 9:23 am
Location: Herford NRW

Misfire/Blowing Exhaust

Post by Madone » Sun Jun 29, 2008 2:45 pm

Weather was nice for a change so went out for a Sunday afternoon drive with the missus. Done about 40 miles and was about 2 miles from home. Accelerated and went to change up and noticed the engine note was different. No warning lights are showing and the engine runs but it doesn't sound right. It sounds somewhere between a misfire and a blowing exhaust although the exhaust doesn't seem to be blowing. Car is a Exige S (3200 miles) and has the Lotus Motorsport exhaust (http://www.bell-colvill.co.uk/LotusShop ... LOTAC05450) fitted. I know it is probably impossible to diagnose from those symptoms but thought I'd try before I contact the dealer. Would have thought if there was a misfire the engine managment warning light would have illuminated.

Don't really want to drive the car to the dealer as I don't know what the problem is and don't want to cause any further damage.

Anyone had any similar problems.

ade
Posts: 7125
Joined: Thu Sep 21, 2006 10:40 am
Location: Essex
Been thanked: 3 times

Re: Misfire/Blowing Exhaust

Post by ade » Sun Jun 29, 2008 6:19 pm

Does it sound like a rattle, sort of? might have broken the exhaust where the tailpipe is connected to the box? it was quite common on the Elise variant of this

Madone
Posts: 25
Joined: Fri May 30, 2008 9:23 am
Location: Herford NRW

Re: Misfire/Blowing Exhaust

Post by Madone » Sun Jun 29, 2008 6:57 pm

Definitely not a rattle and the exhaust doesn't feel as if it is loose, as I said it sound either like a misfire or possibly blowing from somewhere before the silence like between the head and the manifold or something.

21TonyK
Posts: 387
Joined: Thu Feb 15, 2007 10:08 pm

Re: Misfire/Blowing Exhaust

Post by 21TonyK » Tue Jul 08, 2008 2:29 pm

I think I might have a similar problem. So far I've tried various combinations of 2 different cats, a decat pipe, a Larini SE and a Lotus Stage 1 exhaust!

Basically I'm getting a farting-ticking noise under heavy load, ie. foot flat to the floor in fourth at about 30 mph.

Looks very much like the gasket on the manifold is leaking on the joint with the cat. I can see a "V" shape of soot leading to the edge of the cat intake. I've got a new gasket or order at the local Toyota garage which should be in tomorrow so I could have an answer by lunch time.

Don't know if this will help you but I'll post if it solves my problem.

Madone
Posts: 25
Joined: Fri May 30, 2008 9:23 am
Location: Herford NRW

Re: Misfire/Blowing Exhaust

Post by Madone » Tue Jul 08, 2008 5:19 pm

The sound is there even at idle. The dealer has had the car since last monday and still can't find the problem. From what I've gathered it has a misfire on No 1. They have carried out a compression test, changed the plugs, the coils (if they're still called that), various sensors. When I spoke to them today they were removing the camshaft but can't find anything there either. I think that they believe the problem may be in the main engine wiring harnesses but want to change that as a last resort. I'd have thought that if the problem was there it would have shown up on the OBD but I may be wrong.

21TonyK
Posts: 387
Joined: Thu Feb 15, 2007 10:08 pm

Re: Misfire/Blowing Exhaust

Post by 21TonyK » Wed Jul 09, 2008 10:35 am

I think I might have a similar problem. So far I've tried various combinations of 2 different cats, a decat pipe, a Larini SE and a Lotus Stage 1 exhaust!

Basically I'm getting a farting-ticking noise under heavy load, ie. foot flat to the floor in fourth at about 30 mph.

Looks very much like the gasket on the manifold is leaking on the joint with the cat. I can see a "V" shape of soot leading to the edge of the cat intake. I've got a new gasket or order at the local Toyota garage which should be in tomorrow so I could have an answer by lunch time.

Don't know if this will help you but I'll post if it solves my problem.
Replaced the gasket with a new one, aligned everything carefully and refitted. Problem solved. �27 for a gasket though!

arw
Posts: 54
Joined: Sun Aug 27, 2006 10:04 am
Location: Nottingham

Re: Misfire/Blowing Exhaust

Post by arw » Wed Jul 09, 2008 1:02 pm

Glad you've sorted it, but if you think �27 is bad have a look at the prices for motorcycle bits & pieces. Makes your eyes water...

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