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Hbrand
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elusive Engine noise
The left side of my 1974 Porsche developed a sometimes more and than less ticking sound. I have driven 1000 miles like that.
I checked valve play and was ok. Timing chain OK. How can I determine that I have a loose valve seat? Without removing heads thanks, harold
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Cheers 1982 Porsche 911SC Euro 1969 Mercedes 280SL 1956 Austin Healey 3x |
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Join Date: Feb 2006
Location: WinterHaven FLA
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If compression /leakdown is good and consistent on all cyls, no smoke on startup or hot deceleration indication of worn valve guides, then I would suspect a little slop or wear in valve train... is there more noise hot than cold? Try a slightly higher viscosity oil to see if that changes anything, cushioning and quieting the slop, may come back when hot, indicating you are on the right track. Would not assume loose seat unless confirming indications of leak noise or compression. Hope some of these ideas help ..Gordon
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1984 RoW Cabriolet (needed me-followed me home) |
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Brando
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exhaust leak?
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Turbo powa! 1977 911s. it's cool |
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How did you check the valve play?
Was the feeler gauge relatively new? Did you bend the blade so it wasn't cocked between the foot and valve top?
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Chris ---------------------------------------------- 1996 993 RS Replica 2023 KTM 890 Adventure R 1971 Norton 750 Commando Alcon Brake Kits |
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Hbrand
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The ticking noise is more when engine is cold, and varies somewhat. I was thinking that I have a lubrication problem with one of the oil squirters to the camshaft????
thanks, harold
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Cheers 1982 Porsche 911SC Euro 1969 Mercedes 280SL 1956 Austin Healey 3x |
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I'd still spend some time checking and rechecking your valve clearances before deciding on something major, perhaps get another owners ear on it as well. A valve that's even slightly off will tick... though usually when warm...
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Chris ---------------------------------------------- 1996 993 RS Replica 2023 KTM 890 Adventure R 1971 Norton 750 Commando Alcon Brake Kits |
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Its usually a sign of worn guides, especially on the 2.7's that run warm.
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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abit off center
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Are you running carbs?
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______________________ Craig G2Performance Twinplug, head work, case savers, rockers arms, etc. |
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Location: Marysville Wa.
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what steve said.
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https://www.instagram.com/johnwalker8704 8009 103rd pl ne Marysville Wa 98270 206 637 4071 |
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Hbrand
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Ok, I removed the exhaust manifolds and the ports where all carboned up and the tip of the gides oily. So even though the engine was running great with lots of power - the guides are the noise. Which is good because doing the heads is straight forward.
thanks, harold
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Cheers 1982 Porsche 911SC Euro 1969 Mercedes 280SL 1956 Austin Healey 3x |
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No, I do not think I would assume that-- the oil is coming from the cylinders and being burned and deposited on the ports, and oil residue on ports and guides-- are the valves actually sloppy in the guides? are all cylinders the same ?? That would be unusual... any other thoughts, opinions?
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1984 RoW Cabriolet (needed me-followed me home) |
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Hbrand
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will remove one exhaust valve cover, install the spring compressor and check the now free valve for play in the guide.
thanks, harold
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Cheers 1982 Porsche 911SC Euro 1969 Mercedes 280SL 1956 Austin Healey 3x |
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You can try the process of lifting the valve off the seat and move the end of the stem back and forth or attempt to... I did this and noticed a fair amount of movement on one valve. Much later I did a complete top end rebuild and we found out one stem to guide clearance was huge. This was on a 3.2 with 45k miles (had the ticking sound) and I did the top end at 70k miles.. The ticking got slowly worse and worse. When I took the headers off I noticed a lot of oil/carbon build up.. this also pointed to lots of stem clearance, I guess. I also put in new rings and had the nic. cylinders "scrubbed/honed". I just recently took the headers off again to check things out and everything looks pretty clean and I don't have odd noises.
The original ticking started after the engine warmed up....like Steve said. Like you said if it is just top end issues then things can be fixed in a straight forward manner assuming all the parts are correct going back together. That's my 2 cents. -h
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You are going to rebuild the heads. If you choose to have it done by macine shop. There is one with excellent work in your back yard. Then get the motor to Mike at JB Racing in Taveres Florida.
Regards,
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Bernard |
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