My VR has timing problems and is only making 155bhp!

[matth76 0]

Hi

6 months ago I had a rolling road session at Stealth and my 1997 odb2 golf vr6 made 192bhp. It's done 80k miles.

 

About a month ago I had my timing chains done by another good reputable garage.

 

Yesterday I had a rolling road session with Stealth. I found my car was making peak 155bhp and had slight pinking/pinging issues high up the rev range. I was told anything under a '5' is normal. However Stealth's computer showed mine was reaching 8 or 9 meaning it was pinking. I asked if pinking would cause any damage to my bottom end they said no, only a problem if it continued long term. And to be honest I haven't taken it much above 3000 revs since I had my chains done a month ago.

 

Stealth said my lack of power and pinking was due to the valve/cam timing. They did their best yesterday to line up the cams but one of them refused to line up not matter what was done and which markers were used... they put in new cams in case one of the cams was slightly twisted but made no difference... So they assumed it will probably be due to the bottom chain. They said even if it was a few mm out it would cause this problem. Could anything else potentially cause this situation??

 

They are taking the gearbox out to look at it all this week and hopefully get it all right again and making good power. It is certainly something mechanical as VAG COM showed up no faults at all.

 

I'm hoping this is the cause. Does this seem likely or what else could possibly cause this? Anyone else had issues similar to this? What turned out to be the cause?

 

I'm hoping it's nothing else more serious that could be causing this. And will the slight pinking be very damaging in the month since I had my chains done or is it nothing to worry about as long as its sorted now?

 

Thanks for any help and information.

 

Matt

[a_riot 0]

Hi

6 months ago I had a rolling road session at Stealth and my 1997 odb2 golf vr6 made 192bhp. It's done 80k miles.

 

About a month ago I had my timing chains done by another good reputable garage. Following that I have found I have far more power lower down and probably slightly less higher up. However the garage that fitted the chains said they had real trouble lining the cams up so advanced it very very slightly then when they manually turned the engine over it lined up perfectly. I assume the slight increase in power lower down is because it was advanced very very slightly.

 

Considering you just had the chains apart I would hazard a guess that it wasn't put back together correctly. If it is 1/2 tooth off you will have problems, so I think it is one of those things that you have to have exactly right. I would take it back to the mechanic who did the chains, and make them time it properly. Maybe the crank pulley isn't right or there is too much slack, or who knows, but if it won't time correctly something is out mechanically. Maybe someone else can be of more help.

Paul

[matth76 0]

Stealth reckon it's the bottom chain that is out causing the problems higher up preventing the cams lining up properly. Should find out tues morning what is causing this when stealth remove my gearbox.

[Rpmayne 0]

Can't see how the bottom chain would make any odds to the cams lining up in respect to each other. The bottom and top chains are linked via an intermediate shaft. They are effectively two separate links, so the cams lining up together can only be down to the top chain.

 

The cam sprockets are keyed to the shafts so no adjustment can be made, so any difference must be at least the pitch of the top chain (not mm's).

 

Maybe the magnet on the cam sprocket for the cam position sensor has been damaged if they took the cam sprockets off, although you would think VAG-COM / Stealth would pick that up.

[Kevin Bacon 5]

If the intermediate shaft is pointing anywhere other than 12 or 6 O'clock, you'll get timing issues.

[Rpmayne 0]

I thought the intermediate shaft only made any difference on cars with a distrubutor. All that my coil pack car had running off that was the oil pump.

[Geo 0]

No the cam chain is driven off the intermediate shaft so if it isn't timed correctly then the cams won't be right. The garage who did it originally mustn't have put it back correctly. See here:

 

 

Incidentally, why did you get the chains done? I thought the highline golfs had the later type tensioner pad and you didn't have to change it?

[Kevin Bacon 5]

Rpmayne, yeah it only drives the oil pump, but the sprocket still needs to be in the right place in relation to the crank sprocket or it will throw the cam timing. Dizzys are run from the front cam anyway mate.

 

Geo, cheers for that, a picture paints a 1000 words! Unfortunatley the solid polymer pads do still wear out, so late highlines and 24Vs will go through the same aggro as the plethonic coated early pads.....but the difference is the chain just gets a little slack around the cam sprockets, as opposed to the pad crumbling to peices and causing metal on metal slapping!

[Geo 0]

I see, thanks for clearing that up then ;)

[Heardy 0]

If the camshaft's are lined up correctly and the crank is lined up i can't see how the intermediate shaft being out is going to make any difference :?

[Kevin Bacon 5]

Yep, you're right....but it does make a difference. Ask stealth, they've timed 100s of VRs and issues always arise if the inter' shaft isn't north or south.

 

The only other thing I can think of is the crank pulley. Not many people seem to know that the crank pulley has a TDC mark on it (not even stealth knew that) and it's a different angle to the pressure plate TDC mark on the clutch that most people use. I had a problem timing my standard cams when I took the 268s out. I was using the pressure plate TDC mark and the chains just wouldn't roll onto the correct alignment. Turned out that the crank pulley mark was a good 10 degrees off the pressure plate marker. So I redid it all from scratch by working out the middle dwell angle on cyl 1, made sure the intermediate was pointing to 0 degress north and low and behold, the crank pulley marker was bang on and the cam chain slotted on perfectly.

[andy 0]

If the camshaft's are lined up correctly and the crank is lined up i can't see how the intermediate shaft being out is going to make any difference :?

There's a thread on VWVortex that explains why its important, I'll try and dig it out, when I've done mine before I use every timing mark, ie the flywheel one, the crank pulley, the intermediate pulley and the upper pulley. Then spin it all round at least 4 times and check every mark is still alligned. You have to do it four times to bring all pulleys back to their original position. I think its unforgiveable for a garage to get it wrong, if I can get it right on the driveway...

[Heardy 0]

I used the mark's on the flywheel when i did mine i pressume thats okay?