MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Dave4597 on May 26, 2020, 09:52:58 am

Title: Blue smoke and rpm dropping
Post by: Dave4597 on May 26, 2020, 09:52:58 am

Hi everyone, I recently noticed that there is blue smoke coming out of the exhaust (intermittently). Say I'm crusing for a good while then stop at a set of lights as soon as I pull away the car puffs blue smoke (intermittently) then drives normal and no more smoke to be seen.

The car has a 3" turbo back and it's mapped. It done this before it got mapped aswell but wasn't as much.
The machanic told me it can be normal due to the down pipe.. Is that true? but a big amount of blue smoke?
I have done the compression test on all of the cylinders and they are all spot on within the spec as (followed one of the previous threads)

Also when I'm crusing and Im about to stop the rpm will drop sometimes to even 500rpm or lower and the car will stall out of random.

Has anyone ever came across these issues? Help would be much appreciated before I start stripping the engine down.

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Title: Re: Blue smoke and rpm dropping
Post by: pudding on May 29, 2020, 07:47:00 pm

F'cked turbo or shot valve guide seals.

Unless you do very frequent oil changes, valve guide seals dry up and turn to plastic and turbo bearings wear out......it's a sad fact of life unfortunately.   

TFSI engines should not and do not chuck out blue smoke, ever.  If they do, either the turbo or the guides are worn out.

If the compression test read OK (how many bars?  Should be 10+) then it's likely the turbo.  Remaps push tired ones over the edge.

The rpm dropping and cut-outs is probably a bad MAF.

Title: Re: Blue smoke and rpm dropping
Post by: Dave4597 on May 29, 2020, 08:09:09 pm

Quote from: Pudding on May 29, 2020, 07:47:00 pm

F'cked turbo or shot valve guide seals.

Unless you do very frequent oil changes, valve guide seals dry up and turn to plastic and turbo bearings wear out......it's a sad fact of life unfortunately.   

TFSI engines should not and do not chuck out blue smoke, ever.  If they do, either the turbo or the guides are worn out.

If the compression test read OK (how many bars?  Should be 10+) then it's likely the turbo.  Remaps push tired ones over the edge.

The rpm dropping and cut-outs is probably a bad MAF.

Thanks for a quick response!

Sounds like an expensive fix but will be worth it at the end

Compression tests results I got were cylinder 1+2 at 180-185psi and 3+4 180-190psi is that's good enough?

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Title: Re: Blue smoke and rpm dropping
Post by: pudding on May 29, 2020, 08:27:06 pm

Yeah those readings aren't too bad mate.  New engines see about 200psi, so yours isn't far off.  I suspect it's probably the turbo.  A new one is around £900 so not mega money.

Seriously though, start doing oil changes every 3000 miles with Mobil 1 0-40W and it'll look after your engine for life  :happy2: