Stranger things

[doberman19]

Hi to all, my mk6 GTI has started to make the strangest noise. when driving under load in a high gear, say going up a gradient, the engine starts to go WOW WOW WOW WOW there's no noticeable change with the rev counter, and I can be doing as little as 2.5th revs, there is a noticeable holding back of the engine, but if I drive it like miss Daisey she drives great. as yet I've only changed the plugs, I do know my next call is for diagnostics, but meantime I was wondering if this has been experienced by other owners. thanks.

[Snoopy]

Not sure what it would be exactly  from the description but my suspicion would be the diverter valve diaphragm is split. So I would remove that and check it.

[doberman19]

Thanks for that Snoopy, it sounds like a good shout.

[doberman19]

I've had the car on diagnostics and found two codes po100 and po172. if I remember it's
bank 1 running rich, and an air leak with the inlet manifold. not wishing to piddle about
trying to find the issue I've booked it into R-Tech Nuneaton to have the manifold off and
have the head walnut blasted, valves flow test and ultra-sonic cleaned injectors, fit new filters and fit
new Teflon seals. hopefully then it will all be sorted, regards.

[joe6]

Wow. Be like new after that. Might want to check spark plugs and replace if necessary? Be interested if you notice significant difference after the walnut blasting.

[doberman19]

hi, Joe, when I first had issues I replaced the plugs with NGK Iridium,
 they've only done a few hundred miles, I will report my findings after
my visit to R-Tech. regards.

[doberman19]

Just an update, after my visit to R-Tech, I had the ports walnut blasted, but on checking the injectors it was found that two of them were leaking and non-repairable, even the built-in filter mesh on the injectors had disintegrated, so four new  bosch injectors were fitted, On completion I took her for a test drive and I could genuinely could feel an improvement. I still had a warning light on because of the MAF so I replaced it with an OEM unit but the dash light still came on even after being deleted. I later found out that when it's replaced it had to be reset, she's now running really sweet. Hopefully I can keep my wallet closed for many more miles. regards to all.

[joe6]

Thanks for the update. Great that you have a noticeable inprovement . Think I might get a compression test before making decisions about any port blasting. Not using any oil between changes so hopefully the test will be fine and a good cleanup will then be beneficial.

[doberman19]

Hi Joe, R-Tech came highly recommended and they don't disappoint, I see you're in the midlands, so if you are considering having it done pay them a visit, my mk6 has 110k on so it was due a little TLC, regards.