Engine diagnostics ...

[Tappers]

My car (ZL1) has got a horrible flat spot on the power delivery where the car suffers considerable lag when flooring it at low speeds. Can anyone recommend a good garage that will perform a dyno check or some form of engine diagnistics to find out what the problem is ... and then fix it?

[Tappers]

Yes it is still under warranty but I don't trust the mechanics at Chevrolet to look into a problem that could potentially be their liability. I thought I would seek some specialist independent advice first to establish what the problem is and then make a decision on how to proceed once I understand the cause.

[Tappers]

After_Shock said:

does it have an engine warning light on?

No there's no warning light on. It doesn't feel as though there's a mechanical problem with the engine as such - it just has terrible lag at low speed (like a severe turbo lag). You can put your foot down at 40kmh and literally nothing happens until the car changes down a gear .... upon which it goes off like a scolded cat. It's fine at higher speeds but with 580bhp it ought to have power everywhere - it does have a supercharger so I'm wondering whether this isn't working properly.

I will do as suggested and get Chevrolet to look at it in the first instance - thanks.

[Tappers]

Key sympton is as follows:

Car is automatic and running in 3rd gear at say 30kmh, slam foot to the floor. Literally nothing happens for 2-3 seconds (car stays at same speed) as though the engine is holding back. Car detects foot down hard so drops a gear ... then it's off like the proverbial. Big problem when trying to overtake as 2-3 seconds can be a lifetime.

If you floor it from a standstill it's fine ... no lag just pulls like a train.

It's also ok if you hold it in gear - it's definitely associated with the kickdown. Forgive my ignorance as I'm not mechanically minded, but does this mean it's likely to be an engine issue or something associated with the gearbox?

[Tappers]

It's always been this way but I don't drive it that much so it's not been a huge issue to me, but I think it's getting worse.

[Tappers]

shirt said:

seems its quite common

http://www.camaro5.com/forums/showthread.php?t=364...

check the vacuum hose but if not its a case of 'they all do that sir' and your solution is an aftermarket remap.

That's an interesting thread. I love the way it's suggested that it's for safety reasons. I've got a better solution ... if you don't want to unleash 580 ponies when you floor it ... buy the V6. Personally I was hoping for Armageddon so it's a bit disappointing to be momentarily outgunned by a Nissan Tilda!

Edited by Tappers on Sunday 10th May 15:06

[Tappers]

After_Shock said:

Tappers said:

I don't drive it that much

Not a red one is it? One gets parked near where I live seemingly for weeks on end at times!

It is red, so if you live near Marina Promenade ... it could be.

[Tappers]

dxbtiger said:

*************Disclaimer I am not mechnically minded whatsoever!*******************

I reckon it could be as simple as reflashing it with a more aggresive gearbox mode, .

Now this is my sort of mechanics ... I need a widget type thingy to make the gearbox more aggressive then it'll kick down quicker and go like a stabbed rat.