Insightful - I can see what you’re saying. But, the eccentric pulley would go past it’s peak offset and continue on around if the belt was worn. This isn’t the case with my belt/pulley. I’ve just gone the wrong way around with hopes of getting a better fit to to hydraulc tensioner. Previously, following the manual, I’ve never had the “loose” feeling in the locking pin of the hydraulic tensioner. It’s always been a little stiff to remove… not stuck, just firm to remove. This time around, it all went together really well, the rod maintained a 5mm extension and the belt behaved like it should.
Today, prior to my latest exhaust hack, I removed the timing belt covers and checked the timing belt. No signs of wear, timing was still good, and prior to first start the timing belt/tensioner had relaxed. After first start everything pulled in, without that horrible clatter a loose timing belt gives.
I’ll keep an eye on it.
Now for the results of my latest exhaust hack. I was going to take photos, because I was very proud of my work, but… meh.
I trimmed off a couple of 1" lengths of 2.5" pipe, cut them along their length and removed some material at the separation. I then closed up the pipe and pressed it into the flanges. It produced the desired results and everything fit back together well. I now had a close to factory sealing arrangement at the flanges where the manifolds meet the y-pipe.
Those inserts are in there tight I might add. Closed up, not overlapped at the join. I really should have taken photos. It was a work of art.
Torqued it all back together no problems. Announced my supreme confidence in how this was it, the day I fixed my exhaust leak…
Did it fix my exhaust leak? No.
I’m trying to decide if I need a bigger engine or a new car.
Could you find someone who has impaired hearing to sell this car to? Seriously, I thought this last try might make a difference…I got nothing.
Yeah, I’m out of ideas.
What I will do though is a lot of research and reading on exhaust systems. Specifically why this engine is the only 6G74 I’ve seen that can produce the fahsisssle sound when headers are installed. I need to get my brain to understand why it needs to live with the sound now.
If I was serious about selling the car I wouldn’t have fixed the broken bonnet strut;
Buyer: "what’s that exhaust leak sound"
Me: "I dunno, lets pop the hood and have a look…"
Buyer: "yeah, I think thats an exhaust leak, you should get that fixed"
Me: "take a closer look"
SLAM!
Me: “Can you hear it now?”
I was wondering, did you ever swap back to the original cast headers and see if the sound goes away? I was wondering if it was a vacuum leak and not an exhaust leak.
I was wondering, did you ever swap back to the original cast headers and see if the sound goes away? I was wondering if it was a vacuum leak and not an exhaust leak.
Knfenimore - Yes, replacing the stock cast headers makes the noise go away. BUT, not immediately. The fasissle sound continues for a few minutes after reinstalling the stock headers. After that though, its gone.
In regards to a vacuum test, I get 66kpa at idle, with the gauge holding steady and return smoothly to 66kpa after a quick “blip” of the throttle. But, I have to redo the test by racing the engine, my memory of the results of that test isn’t clear.
I want to redo my vacuum test as I’m wondering if I have a slow to return valve. Might explain the noise and the fact that even after installing new lifters/rocker arms/shafts I still have some faint lifter rattle. Do a wet compression test is a PIA with this car, but I think I’ll allocate some time to do one.