[AACstyle]

Hello everyone, new to the forum.

I took delivery of this modified 2008 Exige last week: http://www.lotustalk.com/forums/f94...-drs-turbo-build-street-track-monster-219657/

After the transporter delivered the car I took it for a quick drive, it was about to rain so I did not go far. I could feel some hesitation and the engine felt like it would bog when I tried to accellerate. This was very odd and when I rolled up and stopped at the first red light the car idled erratically in neutral then died. It cranked back up and I immediately pulled into a nearby Shell station and topped off with Premium 93 octane fuel. I was not familiar with the Racepack gauges so I thought perhaps the fuel was low and that was what the issue was. I proceeded back home and parked the car in my garage.

I contacted Kris at DRS who responded to me quickly and suggested it may have been bad fuel (which I had already tried to convince myself it was) and that put me at ease. He gave me information to download software to log data and he offered to take a look at it and perhaps adjust the tune. That was exactly what I wanted to hear so I felt really good about it. The next few days it rained and rained, I could not drive the car so I detailed it and went through everything which gave me a chance to appreciate just how much work went into this car, it is truly impressive. The car was put together so well and with great care, I was so impressed with everything that I genuinely forgot about the issues on the test drive. When the weather cleared I had to travel for work and could not drive the car so yesterday I finally decided I should start it and let it run a while.

I started the car and noticed it was not idling very smooth, I got out of the car (first time I had been outside of the car with it running) and could faintly hear a tapping from the engine compartment. I opened the hatch and listened at the valve cover for valve tap but it seemed to be coming from the manifold area. I removed the manifold thermal cover and the sound immediately got louder.

Video:
https://www.youtube.com/watch?v=jesavCmhJCg

This is my first Lotus so I am by no means an expert but that sounds bad to me.

Unfortunately Kris from DRS is gone for a Lotus Cup race this weekend so I can not get feedback from him until Tuesday.

Experts, please let me know what I should do next?

Thanks in advance!

-Justin

 

[tommyc]

Pull the valve cover! That sounds like a bad rocker arm or wiped cam. Pretty easy 15 min u can reuse gasket. Look for scoring on the high lift intake cam. Will post a pic later


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[oldmansan]

Sounds like a lawnmower or something. Best of luck.

San

 

[tommyc]

If one of your intake cams looks like this check for broken rocker arm


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[AACstyle]

If one of your intake cams looks like this check for broken rocker arm

Thanks, I will check that!

 

[Nessal]

Haven't watched the video clip but it might be an exhaust leak if you are saying that it is coming from the manifold.

 

[mikelr]

Definitely an exhaust leak.....

A wiped second cam lobe would not effect the idle. A broken rocker would but that is not the source of the noise.

 

[tommyc]

Yeah no that i found a quiet place, aka the pot, it does sound like an exhaust leak at the manifold. Easy to check blow some smoke or vapor around manifold near head. If there is a leak you will see it. Also check bolts on manifold see if they are tight


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[AACstyle]

Yeah no that i found a quiet place, aka the pot, it does sound like an exhaust leak at the manifold. Easy to check blow some smoke or vapor around manifold near head. If there is a leak you will see it. Also check bolts on manifold see if they are tight


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Pulled the valve cover and checked everything out. All the lobes look good

Checked the manifold bolts and sure enough I was able to torque them down a bit. There was still a slight ticking sound but it went away for the most part once the engine came up to temp. The idle settled down after running for a while as well. Took it for a test run and it's running much better. Only thing is if you rev the motor then let go of the gas it wants to kill. Going to burn off some more of this fuel and put fresh gas in. Hopefully this is all, it's looking more promising.

 

[shay2nak]

That motor is not at all stock, so it may sound different than what most of us are used to.
Other than datalogging, I'd suggest doing a smoke test on the exhaust side and taking it to a dyno just to see how it measures. If it's a leak, the smoke will pour out of the source.

 

[bbs350z]

^seafoam!
'

 

[mikelr]

Looking at the video again you can see the exhaust staining on the head from the manifold leaking. There is so much soot I would say this has been a long term reoccurring issue. With all the money the PO threw at this car I am really surprised he did not install a full set of manifold studs on the manifold. I would suggest that you replace the gasket and install studs and Nordlock washers to stop this from happening. I'm sure that leak was playing hell with your closed loop fuel control.
One downside of buying a car with that much aftermarket modification is that when things go wrong (and they usually will) diagnosing issues becomes increasingly more difficult as you don't even have the benefit of a factory ECU with OBDII to point you in any kind of direction. I would suggest that if you are not familiar with the stand alone ecu unit and the software that is running this beast, you get familiar.
Good luck!