My 172 won't go above about 5,500 rpm when in gear.

[SuperJ]

Started s few days ago, when the car gets to about 5,000 rpm it just increase the revs really slowly, almost feels like its just hitting the limiter, which of course its way off.

Any ideas what could be causing this?

 

[MicKPM]

I assume its properly warmed up? If so, diagnostics.

Mick

 

[MartinR]

Awaits the timing band wagon...........

 

[SuperJ]

Yea it still happens if the car has been running for an hour.

I had the timing belt changed about 6months ago and its been fine up until the last few days, could it just suddenly slip or something?

 

[The Dominator]

Awaits the timing band wagon...........

lol

 

[MicKPM]

Does it rev freely when it's not moving?

 

[SuperJ]

Yep its fine. Only has an issue when in gear.

 

[SkidMarx]

Does it misfire when it reaches 5500rpm? Possible dodgy coil pack / Leads?

Check engine earths are good also!

 

[MicKPM]

Yep its fine. Only has an issue when in gear.

Then it's most likely load related rather than a timing issue. Diagnostics needed really but I suspect a MAP sensor issue.

 

[SuperJ]

Mmm...well it did have a new coil pack a couple of weeks ago. Perhaps thats the issue. Is there a way I can check myself before taking it to the garage?

 

[MicKPM]

Nope, take it back and put your old coil back on.

 

[SkidMarx]

As Mick said, deffo sounds load related. I had a very similar fault years ago, wouldnt rev up and shift light was coming. Turned out to be a bad engine earth, took ages to find.

 

[SuperJ]

Ah fair enough. This car is pissing me right off recently. Every other week it seems to have an issue. Must have sunk about £1500 into it in the last six months.