Engine pulls better after cambelt change...?

[muddyboots]

Had the cambelt changed on the Passat last week, and I swear it's pulling more strongly above 3k rpm, and holding the power for longer.

It was giving good power figures before the change ( 175bhp & fly and 270lbft @ wheels : http://www.awesome-gti.co.uk/rollingroad/rr.scn_18.11.06.html ) so was obviously fairly healthy - especially given it's mileage of nearly 120k.

I'm now wondering whether it's because the old belt might have got slightly stretched with age, or whether the previous belt was a tooth out when it was replaced first time round - either of which could have affected the cam timing ?

Any idea what kind of effect being one tooth out would have on performance of a TDI 130 ?

 

[Neo_VR]

I doubt the engine would run at all with a tooth out...

Its probably the effect of getting it serviced.. my car always feels better after fresh oil

 

[muddyboots]

Hi Colin

It's not been serviced yet though, just had the cambelt (& other two drivebelts) changed....

 

[stoneyfordNI]

i think the most noticable thing you get lee , being a tooth out is a nice code in the engine block telling you the crankshaft and camshaft sensor are not seeing eye to eye , TBH i had my belt done 2 weeks ago ( no service done) and mine is feeling very revvy too ( yes i know its a turf cutter)

 

[allh2k]

How much was the belt change?

 

[stoneyfordNI]

50 quid plus the kit , seat master tech has a garage at home

 

[Bogwoppit]

I think belts do stretch very slightly.

 

[craig-pd130]

On motorbike engines it's common for ham-fisted home mechanics to rebuild them one tooth out on the camshaft sprocket, which would make the engine less than ideal but would NOT cause valve / piston clashes.

Is there both a crank AND a cam position sensor on the PDs?

Lee, disappointed at the lack of smoke on the dyno run video Good power though!

 

[muddyboots]

Perhaps it was just the effects of a slightly stretched old belt.

Cambelt change on the Passat is a big job, and very expensive when combined with water pump replacement, fitting of new front dampers, replacing of a CV boot, oh and an MOT

Craig - yes good power, but was a bit disappointed how it peaked quite early and drops quite a bit by 4k, but there's a modified map on the way to sort that Then we might see a bit more smoke

 

[_weeman_]

more likely to have been the timing out slightly, there are three bolts on all PD cam pulleys to allow fine timing adjustments.

 

[OLDOILER]

Perhaps it was just the effects of a slightly stretched old belt.

Cambelt change on the Passat is a big job, and very expensive when combined with water pump replacement, fitting of new front dampers, replacing of a CV boot, oh and an MOT

Craig - yes good power, but was a bit disappointed how it peaked quite early and drops quite a bit by 4k, but there's a modified map on the way to sort that Then we might see a bit more smoke

Who's remap are you using my old Passat pulled clean from 2k thro to 5k on a Upsolute mapping (new belt replaced at 38k under warranty)

 

[Ibiza Monkey]

Sometimes you just hit the sweet spot on the pump timing. I did one on a Escort TDI which ran like a bag of cr#p before the cambelt change. It was a completely different car afterwards.

 

[muddyboots]

Who's remap are you using my old Passat pulled clean from 2k thro to 5k on a Upsolute mapping (new belt replaced at 38k under warranty)

This is an Upsolute map, based on their "standard" map but with torque capped between 2-3k to stop the clutch slip I was getting.

I might do a couple of runs with vag-com and measure the torque curve, see if the shape has changed since it was on the RR.