Billman250

Dam these friggin things

Ok, Saturday I had a 2002 out to my place, his TCT was making serious noise. It was the loudest one I'd ever heard, and was doing it constantly at idle. It was so bad, I knew what it was before I even met the guy. He was on his way to one of our meets, and I heard him coming down the street it was so bad. I told him as soon as he got out of the car it needed a TCT. I replaced it, the noise was immediately gone.

So tonight, I disassemble this bad TCT, and a brand new one. I check spring lengths, wear on the worm shaft, play in the piston in the alum housing, friction differences between the two. I come up with nothing.

So now I concentrate on the housing. I remove the small allen head check valve on the engine side of the tensioner. I look for debris, but didn't find anything. I put the check valve back in, then take this bad tensioner and put it in MY CAR.

-Initial startup...no noise at all.

-as the car is warming up, I get a slight flutter from the chain. Two bars show on the temp gauge. Definitely TCT noise. I take the car for a spin, get it good and hot, come back to my place. No noise at all, not even the slightest flutter.

-Let the car sit for ten minutes, then do a hot start...no noise at all.

At this point, I'm leaning towards the check valve. Now keep in mind, this valve is staked like the rear axle nuts. You can loosen it and it will unstake itself as it's only aluminum. I did not restake it, but will soon remove it.

So....I'm wondering if I would have taken the bad TCT, untouched, and put it in my car right away. I wonder if It would have made as much noise as the original car it came from.

So here's a theory: the TCT is not holding hydraulic pressure. It is bleeding off on some cars overnight, causing the starter after-run noise.

On some cars, the pressure is bleeding off while the engine is running, causing noise at idle, and at any other random time.

At this time I don't have a definite conclusion, but I think I'm close. And I would not recommend messing with the check valve...yet

INPUT from the UTH frontrunners please.....

Slows2k

I wish I one to take apart. Most of the ones I replace get turned back in under warranty.

Billman250

I'll be glad to send one or ten

Slows2k

You know where to find me I've had them apart beforem I'm trying to remember how big the check valve is

RED MX5

raymo19

I thought about replacing mine when I had the blower put on. It's never been a problem in 6+ years so I decided to leave it alone. I'm anxious to see the verdict on this as well.

Thanks Billman.

mxt_77

What is the check-valve? Is that the piece that screws into the back of the TCT? Is it pictured here?

Billman250

It is not one of the pictured loose pieces.

It's a small allen head, still in the housing.

Slows2k

Now I gotta dig through my junk to find a Tensioner. I think I may have one from the last motor build.

fperra

I've never experienced the problem, but it sounds to me like the piston that drives the chain is jamming in the bore. I wonder if it would be worth sending the internals off to be REM treated. This process puts an ultra fine polish on the part to the point that they will look chrome plated. Less friction, less stick. I'm currently building an engine with all new parts, so I have a spare one that I'll take apart and have a look.