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Discussion Starter #1
Hello all, a good friend recently purchased a barn find all original 20,000KM 1985 GTV 6. The car has sat in storage for 30 years and is in great shape. After getting it started, the engine sounds like a tractor! Noise seems to be coming from the passenger side valve area. We removed the valve/cam cover and manually turned the engine and everything looks great. Was planning on measuring the exhaust clearances but I am not sure what else to check.

Suggestions?
 

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maybe post some video or audio of the sound? Keep in mind the gearbox will make some pretty good rumbling even in neutral (aka "netural rollover").
 

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Discussion Starter #3
I could try later. It is most definitely the cam/valve area.
 

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"sat in storage for 30 years"

Change the timing belt before you risk running it anymore. Failure is not an option in these interference engines.
 

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After that length of time, I guarantee you it's in no shape to start, run and drive. Trailer it and start disassembly. As Del indicates, if you break or skip the timing belt (which is well aged by now), the valves are toast.
 

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The car has sat in storage for 30 years and is in great shape.
Well that's an oxymoron!

"Tractor sounds" might be the result of a loose exhaust manifold, cracked head-manifold gasket, or compromised head gasket.

I heartily agree with others' comments: do not operate an interference engine with a 30-year old cam belt. Those things fail due to age, as well as miles. Even 5-6 years can get risky.
 

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Well, the newer ones are better for both strength and not aging, but still, 30 years is asking far too much, even for a new style one. Wow!

Cut that sucker off before you get tempted to try to start the engine again.
 
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I missed the 30 year part. Given that, I would be concerned about the spring in a mechanical timing belt tensioner as well (which this year likely has). Would be smart to do belt and tensioner together.
 

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Discussion Starter #9
Hey all. Not my ride. The car is in great shape means it was parked at 20,000 Kim’s. very original. To me it sounds like exhaust noise but the manifolds seems tight. It seems to be coming from bank #1 top corner where the can is. I have a video but can’t seem to post it
 

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Still, advise the owner to do the right thing before trying to start it. That original belt will NOT be in great shape. If it fails, the results will almost always be very dire.
 

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Yeah - you should pass along that advice to the owner if you haven't already.

Belts obviously deteriorate with age because they are materials that decay with time. Same for a tensioner spring under tension for 20+ years. And because a broken timing belt will likely put valves through the top of the pistons, it will require a full engine rebuild to remedy.

That would be a real bummer on a rare GTV6 in great shape parked at 20K kms.

1632704
 
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Yup, not like an older four banger chain design, where the chain doesn't rot with time. Maybe Alfa should have stayed with a chain cam drive for the V6, lol. Probably room for the parts. Lube would be the problem though.
 

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Discussion Starter #13
So thought I'd provide an update. We manually turned the engine to the P mark on the crank. We removed both cam covers and the timing marks on both cams are about 1/4'' ahead of the mark on the cam caps. By ahead I mean clockwise in front of the mark (retarded?). Is this normal? Did the belt possibly jump a tooth throwing both cams out the same amount of degrees?

And yes the belt will be changed out...

Grazie Alfisti!
 

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Sounds like 1 tooth off, if you had the crank pulley notch lined up with the pointer. It might be unusual (not impossible) for both cams to be off the same amount, but who knows? Maybe they were misaligned at one time on setup. You might want to look at the new Staybelt fixed tensioner from Centerline, instead of either the original hydraulic or thermo-mechanical tensioner.
 

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Discussion Starter #15
Sounds like 1 tooth off, if you had the crank pulley notch lined up with the pointer. It might be unusual (not impossible) for both cams to be off the same amount, but who knows? Maybe they were misaligned at one time on setup. You might want to look at the new Staybelt fixed tensioner from Centerline, instead of either the original hydraulic or thermo-mechanical tensioner.
Thank you for your reply. Is there a makeshift tool or a way to move the cams backward (once the belt is off) to bring them in time?
 

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Oh sure... the timing belt and tensioner job is straightforward, just got to be certain everything is lined up.
Alfisto Steve on the 164 forum has an excellent writeup on belt changes.
 

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Discussion Starter #17
update: we removed the h2o pump, belt covers, etc and found the belt jumped 1 tooth. We will be replacing oil pressure tensioner, water pump and belt. Question: how can we move the cams backward?
 

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The nut on the end of the cam pulley is 22mm, you can put a wrench on it to tweak its position.
BTW, the "tractor sound" could also be a stuck/bent valve. Once you have the timing belt replaced, might be a good idea to check the valve clearances, and maybe do compression/leakdown if the sound persists.
 
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I suppose you know a compression test is the first thing needed after you get the cam timing reset, and a new belt and tensioner installed. That should reveal the status of your valves. Again, Alfisto Steve on the 164 forum has detailed steps on belt/tensioner installations, as well as extensive information on the individual parts.
I noticed you said you're replacing the oil-fed tensioner, which might be original. You have a choice of the leak-free thermo-mechanical tensioner, or the new fixed tensioner also. The advantage is neither of those will ever drip oil again, like the oil-fed detensioner can do (although there are tons of opinions out there from fans of the various tensioners on this motor).
So, keep us posted on the progress!
 
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