Evo 6 Extreme RS450 - engine power cutting out
Discussion
It's been a while since something went wrong with my Evo, god forbid it went too long without a problem!
Thought I'd post here just to see if anyone has any ideas, as my Evo specialist is quite a trek from me so it's going to be a few weeks until I can get it to them.
In short, out of the blue and for no apparent reason, when I floor it, the boost starts to kick in but then at about 4,500 rpm, engine power just cuts with a bit of a shunt.
The only thing I can think that's happened is that I did go through some rather deep water.....accidentally as I had no idea quite how deep this water was that appeared across the road.
The car drives fine under no boost, but try and put my foot down and this happens.
Any ideas? I imagine it's one of those things impossible to diagnose just based on this post, but you never know.
Thought I'd post here just to see if anyone has any ideas, as my Evo specialist is quite a trek from me so it's going to be a few weeks until I can get it to them.
In short, out of the blue and for no apparent reason, when I floor it, the boost starts to kick in but then at about 4,500 rpm, engine power just cuts with a bit of a shunt.
The only thing I can think that's happened is that I did go through some rather deep water.....accidentally as I had no idea quite how deep this water was that appeared across the road.
The car drives fine under no boost, but try and put my foot down and this happens.
Any ideas? I imagine it's one of those things impossible to diagnose just based on this post, but you never know.
Potentially stating the obvious but sounds like a boost/fuel cut issue if it feels like it's hitting a brick wall and cutting power. Check for any loose or disconnected vacuum hoses.
Do you have anything measuring boost levels? It would be useful if you could see what boost levels the engine thinks it's seeing as this sounds like it thinks it's over boosting.
You may have knocked something off in the water or potentially something is blocked maybe?
If water had gotten into the ECU I'd have expected more issues than the car just misreading the boost levels.
Do you have anything measuring boost levels? It would be useful if you could see what boost levels the engine thinks it's seeing as this sounds like it thinks it's over boosting.
You may have knocked something off in the water or potentially something is blocked maybe?
If water had gotten into the ECU I'd have expected more issues than the car just misreading the boost levels.
C5_Steve said:
Potentially stating the obvious but sounds like a boost/fuel cut issue if it feels like it's hitting a brick wall and cutting power. Check for any loose or disconnected vacuum hoses.
Do you have anything measuring boost levels? It would be useful if you could see what boost levels the engine thinks it's seeing as this sounds like it thinks it's over boosting.
You may have knocked something off in the water or potentially something is blocked maybe?
If water had gotten into the ECU I'd have expected more issues than the car just misreading the boost levels.
I do have a guy near where I live who specialises in American cars (he looks after my Corvette) and I take the Evo to him for servicing and basic check up - he's had a look at it but couldn't find anything obvious, so I would have thought he'd have been able to see something like the hoses etc (I did hope it would have been something like that, as it wouldn't be the first time it was a simple fix like that) Do you have anything measuring boost levels? It would be useful if you could see what boost levels the engine thinks it's seeing as this sounds like it thinks it's over boosting.
You may have knocked something off in the water or potentially something is blocked maybe?
If water had gotten into the ECU I'd have expected more issues than the car just misreading the boost levels.
I do have a boost controller, but it barely gets to any boost pressure before the cutting out issue occurs, so not sure overboost would be the issue, but then I'm no expert.
I did think the water might have done something like you say, but as above I would have thought my Corvette guy would certainly have spotted anything obvious like that, so annoyingly I think it might be something more involved.
KarlMac said:
It's worth checking plugs, the 4G63 eats them and can cause all sorts of running issues. For the sake of £20 and something you can do on the drive it's worth checking.
Yeah, good point, no harm me having a look actually, will get on with doing that before spending money sending it away Pepperpots said:
does power come back when you ease off? Might be a boost tube split or being squeezed
Yeah, drives fine off boost, and as you can imagine I immediately life off as soon as this issue happens and just carry on driving as normal. Obviously I haven't dared keep my foot down to see what happens beyond this cut out issue happening. Pepperpots said:
check air intake and turbo hoses for connection and splits, sounds like air is leaking under boost.
I'll have another good look around, but I would be surprised if between me and my Corvette mechanic we'd both missed something vaguely obvious like that, but here's hoping, as a simple fix is always welcome! UTH said:
I do have a guy near where I live who specialises in American cars (he looks after my Corvette) and I take the Evo to him for servicing and basic check up - he's had a look at it but couldn't find anything obvious, so I would have thought he'd have been able to see something like the hoses etc (I did hope it would have been something like that, as it wouldn't be the first time it was a simple fix like that)
I do have a boost controller, but it barely gets to any boost pressure before the cutting out issue occurs, so not sure overboost would be the issue, but then I'm no expert.
I did think the water might have done something like you say, but as above I would have thought my Corvette guy would certainly have spotted anything obvious like that, so annoyingly I think it might be something more involved.
Ian Allen? I do have a boost controller, but it barely gets to any boost pressure before the cutting out issue occurs, so not sure overboost would be the issue, but then I'm no expert.
I did think the water might have done something like you say, but as above I would have thought my Corvette guy would certainly have spotted anything obvious like that, so annoyingly I think it might be something more involved.
The fuel cut is right around the rpm you're seeing this at so it does sound boost related but you could check the spark plugs as well as suggested as that's easy enough. I'd have expected it to run rough at all rpms if it's plugs though this sounds consistent.
I think it's well worth checking all the boost/vacuum/intercooler lines, as mentioned a split pipe may not show until under pressure so give the lines a squeeze and look for cracks/splits. If you can remove them even better as you can check underneath. From memory, there's not too much to trace and it'll be well worth the effort to save sending it off.
Who do you use for the Evo by the way?
UTH said:
Pepperpots said:
check air intake and turbo hoses for connection and splits, sounds like air is leaking under boost.
I'll have another good look around, but I would be surprised if between me and my Corvette mechanic we'd both missed something vaguely obvious like that, but here's hoping, as a simple fix is always welcome! The hoses might crush when the pressure from the turbo builds, then when you ease off they regain their shape.
I might be wrong on this , just guessing of course
C5_Steve said:
UTH said:
I do have a guy near where I live who specialises in American cars (he looks after my Corvette) and I take the Evo to him for servicing and basic check up - he's had a look at it but couldn't find anything obvious, so I would have thought he'd have been able to see something like the hoses etc (I did hope it would have been something like that, as it wouldn't be the first time it was a simple fix like that)
I do have a boost controller, but it barely gets to any boost pressure before the cutting out issue occurs, so not sure overboost would be the issue, but then I'm no expert.
I did think the water might have done something like you say, but as above I would have thought my Corvette guy would certainly have spotted anything obvious like that, so annoyingly I think it might be something more involved.
Ian Allen? I do have a boost controller, but it barely gets to any boost pressure before the cutting out issue occurs, so not sure overboost would be the issue, but then I'm no expert.
I did think the water might have done something like you say, but as above I would have thought my Corvette guy would certainly have spotted anything obvious like that, so annoyingly I think it might be something more involved.
The fuel cut is right around the rpm you're seeing this at so it does sound boost related but you could check the spark plugs as well as suggested as that's easy enough. I'd have expected it to run rough at all rpms if it's plugs though this sounds consistent.
I think it's well worth checking all the boost/vacuum/intercooler lines, as mentioned a split pipe may not show until under pressure so give the lines a squeeze and look for cracks/splits. If you can remove them even better as you can check underneath. From memory, there's not too much to trace and it'll be well worth the effort to save sending it off.
Who do you use for the Evo by the way?
I'll have a good poke around for split pipes etc when I'm checking the spark plugs - I've had many years of tiny issues on track days where I've spotted a hose that's popped off, so maybe I'll spot it again.
UTH said:
No, Ian Goss, the only other Ian for Corvettes haha. Luckily he's 5 mins from my house, so a godsend for the Corvette, and great that he's been able to service the Evo, but as it's so highly tuned he said better to go back to my regular guys for this issue - Auto Torque up in Aylesbury. I used to live closer to them, so they've known my car for many years, but now from Surbiton to Aylesbury it's a serious trek - £180 quote to get it there on a trailer, or a very long drive and public transport back.
I'll have a good poke around for split pipes etc when I'm checking the spark plugs - I've had many years of tiny issues on track days where I've spotted a hose that's popped off, so maybe I'll spot it again.
That's handy for the Vette!I'll have a good poke around for split pipes etc when I'm checking the spark plugs - I've had many years of tiny issues on track days where I've spotted a hose that's popped off, so maybe I'll spot it again.
My geography isn't great and appreciate you've used Auto Torque for years and may want to stick to them but Hayes Dynotech (Erith Kent) may be a fair bit closer now? I used to take me Evo 8 there when I owned it and still use the other "normal" side of the garage for my car now. Bob there has been tuning Evo's for years and is well known, has a rolling road in house and runs one of his cars in the time attack series. If you do need to take it somewhere give them a call and see what they suggest.
C5_Steve said:
UTH said:
No, Ian Goss, the only other Ian for Corvettes haha. Luckily he's 5 mins from my house, so a godsend for the Corvette, and great that he's been able to service the Evo, but as it's so highly tuned he said better to go back to my regular guys for this issue - Auto Torque up in Aylesbury. I used to live closer to them, so they've known my car for many years, but now from Surbiton to Aylesbury it's a serious trek - £180 quote to get it there on a trailer, or a very long drive and public transport back.
I'll have a good poke around for split pipes etc when I'm checking the spark plugs - I've had many years of tiny issues on track days where I've spotted a hose that's popped off, so maybe I'll spot it again.
That's handy for the Vette!I'll have a good poke around for split pipes etc when I'm checking the spark plugs - I've had many years of tiny issues on track days where I've spotted a hose that's popped off, so maybe I'll spot it again.
My geography isn't great and appreciate you've used Auto Torque for years and may want to stick to them but Hayes Dynotech (Erith Kent) may be a fair bit closer now? I used to take me Evo 8 there when I owned it and still use the other "normal" side of the garage for my car now. Bob there has been tuning Evo's for years and is well known, has a rolling road in house and runs one of his cars in the time attack series. If you do need to take it somewhere give them a call and see what they suggest.
Can anyone local to you smoke test your car? Will show any leaks you may or may not have easily. Had this done on mine when it wouldn’t boost over 1bar. No real leaks of note on mine so they swapped the boost solenoid but still the same. Bit more digging and found that the boost controller had reset itself to factory settings of 1bar. Quick drive altering the controller and back up to 1.8 bar.
I know someone who I highly recommend that works on my Evo but they are in the Midlands. I can pass on his number/details if you need any help.
I know someone who I highly recommend that works on my Evo but they are in the Midlands. I can pass on his number/details if you need any help.
Edited by wolfie28 on Friday 24th February 12:01
wolfie28 said:
Can anyone local to you smoke test your car? Will show any leaks you may or may not have easily. Had this done on mine when it wouldn’t boost over 1bar. No real leaks of note on mine so they swapped the boost solenoid but still the same. Bit more digging and found that the boost controller had reset itself to factory settings of 1bar. Quick drive altering the controller and back up to 1.8 bar.
I know someone who I highly recommend that works on my Evo but they are in the Midlands. I can pass on his number/details if you need any help.
I'm going to have a poke around over the weekend at spark plugs, hoses etcI know someone who I highly recommend that works on my Evo but they are in the Midlands. I can pass on his number/details if you need any help.
Edited by wolfie28 on Friday 24th February 12:01
But to be honest I've half resigned myself to sending it to my specialist anyway.....it's not been there for a couple of years so I'm starting to convince myself that actually it's no bad thing to get them to give it a good bit of TLC anyway, I'm sure there are quite a few small jobs they'll find that are worth sorting out, and it'll be nice to get it back knowing it's had a proper 'check up' if you know what I mean.
Piqued my interest this and it reminded me when I had my old car, a turbo nutter b
d 4 cylinder thing which had a boost issue.
Basically I would plant my right foot and the boost would build until it ended up over-boosting, unbeknown to me.
What happened was the wastegate stuck (rusty, needed some grease) and the ecu cut the ignition when the boost went too high to protect the engine. As soon as the boost dropped, it carried on as if nothing had happened.
Was mostly in 4th and 5th gear on the German autobahn.
d 4 cylinder thing which had a boost issue. Basically I would plant my right foot and the boost would build until it ended up over-boosting, unbeknown to me.
What happened was the wastegate stuck (rusty, needed some grease) and the ecu cut the ignition when the boost went too high to protect the engine. As soon as the boost dropped, it carried on as if nothing had happened.
Was mostly in 4th and 5th gear on the German autobahn.
Pepperpots said:
Piqued my interest this and it reminded me when I had my old car, a turbo nutter bd 4 cylinder thing which had a boost issue.
Basically I would plant my right foot and the boost would build until it ended up over-boosting, unbeknown to me.
What happened was the wastegate stuck (rusty, needed some grease) and the ecu cut the ignition when the boost went too high to protect the engine. As soon as the boost dropped, it carried on as if nothing had happened.
Was mostly in 4th and 5th gear on the German autobahn.
Well.......that's very interesting you say that. d 4 cylinder thing which had a boost issue. Basically I would plant my right foot and the boost would build until it ended up over-boosting, unbeknown to me.
What happened was the wastegate stuck (rusty, needed some grease) and the ecu cut the ignition when the boost went too high to protect the engine. As soon as the boost dropped, it carried on as if nothing had happened.
Was mostly in 4th and 5th gear on the German autobahn.
My Corvette guy who looked it over said that he was 'surprised to see someone has welded the wastegate open'
I am very much wondering now if the welding he's referring to isn't welding, but rust/stuck as per your post.....
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