TOP END NOISE AND OIL ?

Messages
131
Location
Sydney
I HAVE A 1987 304 V8 HOLDEN Commodore I bought it second-hand 12 months ago and I do not believe it was well looked after for the last 3 years before I bought it. It blows no smoke. My question. When I change the oil and filter (to GTX2 20/50 SL) I get some ticking from what I assume is a valve or a lifter. I always fill the filter with oil first too. It seems to be stronger when the engine is at temp but is noticeable when cold too. Always after about 1 month following the oil change (and the oil begins to turn black), it goes quiet (but not completely) and I can hardly hear it. It stays quiet for about 3 months and then when I change the oil, the noise comes back. Why ? I have tried another brand of dino oil and it did the same thing. [ January 23, 2003, 09:32 PM: Message edited by: Andrew ]
 
Messages
55
Location
NC
I think I had a lifter ticking in a 4.3L V-6 Chevy S-10 about 3 years ago. When I switched it over to Mobil 1 5W-30, the tick went away in the first 100 miles. I now run Mobil 1 10W-30 in this truck and the tick has been gone now for about 35,000 miles. I don't know for sure what the engine noise was or what fixed it, but I think it was the Mobil 1.
 
Messages
43,651
Location
'Stralia
Andrew, The holden V-8 is fitted with non-adjustable valve train, and has a habit of eating cams. First step would be get in contact with Sprintman and get an engine flush. After that. If your lifter preload is insufficient (through cam/lifter wear), you might get an intermittent ticking that's variable with engine temperature. Get the motor warm, lift the rocker covers, set up a splash shield, and run the engin at idle. put your finger on top of the rocker bridge, and feel for sharp impulses on the rocker bridge, indicating a tappet that's stuffed, or over extended. Make a note of the ones that you feel a discrete impulse, and go from there. Make sure that the bad cylinders are on the base circle of the cam. Try to rotate the pushrods with light finger pressure. If they turn easily (compare to a good cylinder), then there's insufficient preload. Lift the rocker bridge, and see if it's heavily worn (relatively soft alloy). If you've got one or more loose lifters, and the rocker bridge isn't worn, chances are that your cam/lifter has worn. It's not a big job, unless you've got aircon, and you can go for some performance improvements while at it. Always use moly cam lube when reassembling, or you'll be there again in a very short period of time.
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
Perhaps the oil is too thick, but once it's been in use for a while it thins out and that's why the noise stops. How about trying a 10w40 or 15w50 instead?
 
Messages
2,480
Andrew, it sounds like it ticks when you've changed the oil because the oil filter is re-filling and oil pressure needs extra time to be re-established. I would use try auto-rx first to see if it cleans out whatever is causing the valve noise before performing major engine work.
 

Andrew

Thread starter
Messages
131
Location
Sydney
The car has done very few miles. Only 130,000 km. So it must have been doing lots of short trips over 15 years. When I bought it, everything seemed OK until I changed the oil filter which was filled with "grit" like sand [Eek!] Apparently, while it was treated well for the fist 12 years, the second owner didn't take much care of it [Thumbs Down!] I think I will try a thinner oil next time because I agree that it sounds like thinning out of the 20/50 oil is what is making the engine quieter with time. A 15 - 40 or similar. Thanks
 
Top