I have a top end metallic scraping noise only upon cold start-up that lasts for 10-15 seconds. It sounds like it's coming from the cam gear area, I've removed all the accessory belts to eliminate the alternator, ps pump and a/c compressor as potential culprits. It could potentially be the water pump, but the noise disappears so quickly, it leads me to suspect the camshaft /gear bearings. I haven't removed the timing belt cover or camshaft carrier cover yet to inspect, I thought I'd reach out on the forum first to see if anyone here is familiar with this issue. I did read a post on this forum where camshaft bearings are a known problem with these engines. I'm hoping there are some folks here that have had experience solving similar problems and can offer advice and steer me clear of potential pitfalls before I start tearing into it. Thanks in advance for all replies and help solving this.
Take cam cover off and inspect cam. Sounds like oiling issue.
Thanks for the reply. I have removed the alt belt, ps belt and a/c belt one at a time to determine if any solved the issue but sound still persists. I also removed the cam belt cover to determine if the wp was the culprit, but no luck. The car is away for the winter so in the spring I'll pull the cam cover and inspect the cam as you have suggested. I've owned the car since new and changed the oil and filter every year so it is spic and span inside when I remove the oil filler cap and can see the cam. It has 44000 kms (27000 miles) so it sits most of the time and I understand how lubrication could be a problem on start up. I added a 355-ml bottle of Rislone Hy-per Lube Zinc ZDDP Oil Supplement when I changed the oil in hopes that may help, but no luck. I have also removed the coil wire and turned the engine over several times to build oil pressure before cold starting but the sound still persists. When I pull the cam cover, I'll take a picture and post it. Do you know if I can reuse the cam cover bolts or do I need to use new ones when re-installing the cover? Also, is there anything in the upper part of the exhaust that could be making a metallic scraping/clanking noise for a few seconds on start up? Just grasping at straws here as I really don't want to have to remove the camshaft. Thanks again for your help.
I d be inclined to check the waterpump!its metal and they don't last forever.Ive changed mine on my 85 cav type 10 2.0 ohv, pretty easy change.
Thanks! I have a new wp, o-ring seals, antifreeze and deionized water. The OHC engine has the wp driven by the timing belt which is something new for me, I've never r&r one before. I have a new timing belt, the Kent-Moore wp adjusting tool and the timing belt tension gauge, so I'm all set I think? When the weather warms up, I'll pull the timing belt cover again and put a mechanics stethoscope on the wp. The noise disappears quickly so hopefully I'll catch it in time to make a determination if it's the wp. In the meantime I'll get a new cam carrier cover gasket, camshaft seal and camshaft repair sleeve, just in case. I'd be grateful for any advice from folks who have done either of these repairs on the OHC engine.
The cam is oiled through the center , splashes the follower and it is easy to develop a clog. The lobes affected will stay dry and grind down. I bought mine with just over 110K and bad lifter ticks. When the head gasket gave out it was time to pull it out. My cam had ridiculous wear. I mounted up a mechanical oil pressure gauge when the sensor sprang a leak and the pump is running 60 PSI on the highway, so don't automatically suspect the pump as the source.
Thanks for the reply! The cam appears to be well oiled when I look at it through the oil filler, but only pulling the cover will confirm. I'll post a pic after I remove the cover. Too cold to work in the garage unfortunately.