Loss of power... suggestions?

[kizmo2209]

Hi all, have followed the forum for about a month, only been a member for a week or 2. I am having issues with my 51' Leon Cupra. I will try to put it as best as I can:

owned the car for around 3-4 weeks

the car ran absolutely lovely for 1000 miles

out of nowhere on the way home from work the car loses power through the whole rev range; lack of turbo noise and any form of solid acceleration is non-existent

after visually checking everything in view to do with the turbo and pipes, all seemed normal

however we noticed coil pack was raised. pushed said coil pack down and had power once more.

a few miles later loss of power again. coil pack raises once more, push it down, runs fine.

the sparkplug in relation to that coilpack was not tightened in the cylinder at all. took it out, had a look, put it in tightened, put coil back on, ran sweet, coil stayed down.

back into limp-mode again....

this time coil has stayed down

plugged in obd port and no error codes

wtf is going on? current plan is to change all sparkplugs and possibly coilpacks, but there are no codes saying there is anything wrong with them?

 

[kizmo2209]

to make it clear as I have read other people's posts, its not intermittent in the sense that power would come back whilst driving. once it was limping, it stayed limping until I pushed the coil down again. But now its staying down its still doing it anyway!!

 

[mty12345]

Hi mate, welcome to the forum.

Did you turn the engine off when you got out to push the coilpack down? If so, than that was what restored boost rather than anything you did to the coil pack. When it next happens, try turning the car off and back on again. If that restores boost, then 99% certain the car is going in to limp mode for some reason.

If you had a coilpack failure, then 99% of the time you would have a flashing check engine light during the misfire.

If it turns out that it is going in to limp mode, then scanning with VCDS can reveal codes that normal obd2 readers won't.

 

[kizmo2209]

Hiya!

Since not having to touch the coil pack I have driven the car twice. First drive was in the evening last night and was about 15 minutes in which the car was fine. On my drive to work this morning which is nearer 35 minutes, it went into limp again after 25 minutes.

Turning the car off and on again this morning made no difference at all. But it fixed itself from limp mode yesterday afternoon when it was sat for 5 hours (would have maybe cooled down and what ever the issue was then went away?). Somebody mentioned maybe a something is getting effected by temperature? The issue also only seems to come on after being stopped in traffic too. It never loses power during acceleration!

It currently has Bosch super 4s in it and will change the spark plugs to ngk brk7es and see if that does any difference

 

[Alexis27]

I'd just get 4 new coils and spark plugs fitted.

 

[kizmo2209]

I have been corrected on my terminology. Apparently the car isn't in limp mode because I still have my full range of revs. Either way, I struggle to pull away with a loss of power still after another drive where it was acting normal to start with. And once again the problem only came around immediately after being stopped in traffic. What about having the car stationary in traffic is effecting my engine's power...

 

[mty12345]

Limp mode in these cars still allows full revs, but just completely disables the turbo (or a least limits it to 5psi)
Do you know anyone with VCDS as it really needs scanning with that.

 

[kizmo2209]

I had somebody with diagnostics look at live data on my engine yesterday. It seems like my temperature ecu coolant temperature sensor is screwed. Sat on idle before we even left my house it was up to 83 degrees Celsius, and after 5 minutes apparently my engine temperature was up to over 130 degrees!! Where my dashboard sensor wasn't even warmed up over 60 and then showed a solid 90 once we got going. As well as the sensor reading a dramatically high temperature it was limiting my throttle body to only be up to 32% open. So figure replacing the sensor in the next couple days will hopefully sort it!

 

[Andrewwright]

Hope you haven't damaged any internal part at that temp. 32% as the engine was trying to save itself...just don't drive it till it's fixed.

Sent from my Nexus 6 using Tapatalk

 

[kizmo2209]

That's part of the thing. Don't think the engine is actually running at that temperature. It's been losing power like this for over a week. Something would have went bang by now. That and plus the fact that even when it is limping it's still as quiet and smooth as it has ever been. There is no juddering or anything. Even so, don't plan to drive it until it's fixed either way

 

[kizmo2209]

Awesome!! Car is fixed! It literally was just a faulty temperature sensor. I have new sparkplugs anyway but haven't fitted them yet. Just drove the car for 1-2 hours no problem at all. Only cost me £10 as Well! Temperature not reading above 93 degrees and all other readings like throttle position sensor are spot on!

 

[mty12345]

Glad to hear you got it sorted. The throttle sensor would have been limited because the engine (wrongly) thought it was overheating.

 

[kizmo2209]

Thanks! And yeah, makes perfect sense now haha. Driven it plenty more miles today and is holding up solid would never have known though without diagnostics. Was even contemplating having to do maf and things if the plugs and coilpacks didn't do anything (which evidently it wouldn't have!) So happy it wasn't expensive.

 

[Andrewwright]

Yes +1 on the fix.
Nice and cheap too. Vag-com is the best thing to go to with these cars.
When I see the thread I though...damn! Stop driving now but I guess running nice was a good indication things running fine.

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