chris2k03

A couple of weeks ago my car just started idling rich out of nowhere. My AFR's would be at 11-12 at idle, which is set at 1100rpm. Outside of the idle the car is running just fine - cruise AFR's are around 14-15 roughly.

Shortly after I noticed my rich afr's at idle, I noticed a ticking noise from my timing chain area. I've been running an inlinePro TCT for over a year. I also did a valve adjustment after the ticking started. Can a stretched timing chain be causing the noise and rich idle (by throwing off my timing)?

Any insight would be appreciated. Thanks.

Here's a video of the noise.

http://www.youtube.com/watch?v=py69VPmJNAs

1SlowSi

It hit a fuel compensation part of the ECT/IAT temps?

chris2k03

So my car developed a ticking/rattle from and after poking around with a stethoscope, I'm sure it's coming from the timing chain area. I'm running a modded TCT (inline Pro), but I took it off and sandblasted the worm gear anyway to see if it would fix my problem with the ticking. Put it back together and the ticking remains.

Could my chain be stretched? Wouldn't a stretched chain throw off timing, which would in turn cause my rich idle?

05TurboS2k

^ Make a new post for this with a title that provokes some interest such as "TCT ticks after inlinepro replacement".

I'd be having a look at my valves/retainers/springs etc. if it were my motor and I was in your shoes right now.

chris2k03

The inlinePro TCT has been on the car ever since the the turbo install (over a year ago). I actually did a valve adjustment when I first started hearing the ticking. Valves, springs, retainers all look good.

chris2k03

Just posted a video.

05TurboS2k

This doesn't sound like TCT at all to me. I've done my TCT 3 times, this sounds like either a serious bottom end issue or something quite large in the topend that's loose.....Hopefully it's from the TCT. From the video it doesn't sound like it is. This sounds almost more a knock rather than a tick. The TCT allows the chain to rattle and produce much more of a buzzing/ticking sound than what we're hearing in this case.

05TurboS2k

As far as the timing chain stretch, it really doesn't stretch much and I don't see it stretching enough to make a difference in timing to the point of any serious changes like major AFR tweaks.

Stop running the motor and yank the TCT out right now and have a look at it, could be a broken spring in it or something of that nature allowing it to bang around. Like I said, doesn't sound like chain by any means, it could be the TCT device itself perhaps, I'm hoping it's just that.....

Pull the valve cover and look at the chain guides too, are they very worn or damaged? Does one side (exhaust side) still move properly to provide tension on the chain?

It sounds a lot like a broken piston skirt or rod knock to be honest.

chris2k03

I really hope it's nothing serious. I took the TCT out a couple days ago and it looked normal. I sandblasted the worm gear as well to see if it would help. When I poked around with the stethoscope the sound was loudest right by the TCT/Timing chain area. I'll pull the valve cover and check out the guides as well. Thanks.

05TurboS2k

If you blasted the worm geart it should have gotten better right away. The other thing is the TCT issue is generally related to engine temp and rpm as well, essentially it's inconsistent until it slowly gets much worse. If this started rather suddenly it's probably not the normal TCT issue everyone gets.