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Discussion Starter · #1 ·
I've been posting about it for a little while on SC.
YouTube - Startup-Noise 1.wmv
Sound definitely emanates from the timing chain cover area, as can be seen in the video. I placed the camera on the valve cover and you can hear the valve train but no lifter clatter.

Just had it to the shop(same shop that did the HG). Mechanic said all the lifters were hard, the chain tension was "right" (no measurement of tensioner). All the bolts are in the right place, including oil galleys and milled out bolts. Oil pressure is immediate and quite high. The pressure relief valve falls out now and moves smoothly. All pulleys were checked for excess play and noise-apparently none.

There is an exhaust leak-might be the header or might be the junction of the header to the turbo flange. Dunno, can't see. It sounds awful. Mech thinks its the balance chain. Makes no sense to me as the car has no sludge anywhere and was never driven hard.

HELP.

Thanks,
-Cm
 

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maybe the chain is too tight?

How about a stethoscope? So you can pinpoint the spot the noise is coming from. I just want to eliminate timing chain from exhaust leak. Is the chain rubbing against the cover on the inside? So when you had it at the shop your mechanic opened all this up and checked it out correct?

It also sounds like it could be a loose exhaust gasket of some type that is resonating. I think the irregularity of the sounds could be exhaust related.

Another thing. Did you say this noise is on startup of a cold engine? Is it there all the time or does this noise go away after the car warms up. If it goes away after the car warms up, then i'd go the route of an exhaust gasket. As the engine heats up the metal expands just enough to pinch the gasket closed and stop the resonation of the gasket from the exhaust pressures. If this is true, then your problem is not damaging anything. So, do you replace the gasket to get rid of the noise.

Beyond the noise, it sounds like the engine is running well at idle.
 

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maybe the chain is too tight?

How about a stethoscope? So you can pinpoint the spot the noise is coming from. I just want to eliminate timing chain from exhaust leak. Is the chain rubbing against the cover on the inside? So when you had it at the shop your mechanic opened all this up and checked it out correct?

It also sounds like it could be a loose exhaust gasket of some type that is resonating. I think the irregularity of the sounds could be exhaust related.

Another thing. Did you say this noise is on startup of a cold engine? Is it there all the time or does this noise go away after the car warms up. If it goes away after the car warms up, then i'd go the route of an exhaust gasket. As the engine heats up the metal expands just enough to pinch the gasket closed and stop the resonation of the gasket from the exhaust pressures. If this is true, then your problem is not damaging anything. So, do you replace the gasket to get rid of the noise.

Beyond the noise, it sounds like the engine is running well at idle.
I also say exhaust gasket for the same reasons. Could be the bolts just need to be retorqued.
 

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Discussion Starter · #5 ·
Yes, only on a cold engine!!! It goes away within a couple minutes. What you guys here don't know is that I am struggling with 100+psi oil pressure past 5k rpm on a hot engine and 100+psi oil pressure on a cold engine. Idles @ 22ps once warmi.
I almost tore the engine apart, and then found that an exhaust header leak can make a lifter-esque sound on startup (from youtube of all places) and then go away as tolerances clear with heat. It is silky smooth and quiet (for 3" t-back) after brief warmup.
I used a steel rod and then a piece of rubber hose for a steth-doesnt seem like valve train noise and I can't pinpoint it anymore than I already have.

What they think on SC is that my super high oil pressure has stretched the balance chain beyond spec and it is time to slice and dice. I hope not, for more reasons than the thought of ruining the car with a stuck, cut, balance chain.

Damnit though, it sure as hell seems to be coming from the timing cover.
-Cm
 

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Discussion Starter · #6 ·
Could it be a failed tensioner? Do they fail in Saabs? To check the tensioner I take the small bolt off first then the big fat one? I've been listening to start-up vids with "chain" rattle and they sound similar to this.

It goes away with rpms-counter to what I know about bad chains.
-Cm
 

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Well, if you've checked the gaskets, here's a difficult route. What if the noise is the tapping of a backpressure valve in the oil pump. Could there be a problem with your oil pump? Loose parts inside the pump? I don't know the configuration of the oil pump but high oil pressure when cold and only at high rpms when hot leads me to want to look at your oil pathways after the pump and blowbye valves in the pump high pressure stream. it sounds like something affected by heat, such as a valve allows too much pressure to build up when cold. No release or a blockage. Then releases when warm. then when you crank up the rpm and the pressure builds, the valve sticks not releasing the excess pressure.

Or, maybe there is a clog in the high side of the oil pressure system. When cold and you have a heavy(thick) viscosity the oil builds pressure due to a clog. Maybe there is a blowbye valve that we hear tapping in the video. When the engine is hot and viscosity is lower you still have a clog and the pressure builds when up at 5000 RPM. Once RPMs drop pressure reduces and lower viscosity takes care of the rest.
 

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Discussion Starter · #8 ·
This sucks. Seems to be this exact problem. Friggen mechanic used a SHITLOAD of silicone gasket maker to hold the valve cover gasket on-wouldnt be surprised if some flaked off. The fact that this engine had a perfect life and was treated very well makes me HIGHLY doubt this problem is age/mileage/wear dependent. As was said before, it was quiet after the shop, then after a good drive I started it the next day and it made a racket. The oil pressure relief valve does not stick however. Do the pumps on these cars have another pressure relief/blow by valve? The only one I knew of was the one that is commonly referenced. BTW if you notice, the noise appears within about a second of idling immediately after start. I am convinced it is oil related. The second the pressure drops below 100 or so, the ticking stops. This could also be the tensioner on the balance chain and the chain, crying for mercy as they gets crushed by extreme pressure.
Is my engine toast? I took a gander today with a stethoscope and listened on a warm engine with hopes of finding an attenuated version of the noise-no dice.
I can also hear the exhaust leak as sort of a "pftpftpftpft" sound when warm, and when cold it is louder, but the same tone. This noise seems almost certainly within the valve cover.
Thanks for the help thus far. Please keep throwin ideas at me.
I am SOL currently and need the car. I suppose I could drive it till it nukes, but really dont want to:(
-Cm
 
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