SR20DE Oil pressure/whine...

[maxq]

The problem started with a timing chain rattle on startup (I had replaced the tensioner 40,000 miles ago). I replaced the tensioner again and it didn't help... Now I get bad rattle on startup, then it goes away for 5-10 minutes until the oil thins out and then a slight rattle starts. And now there is also a mechanical whine, dependent on engine rpm (I thought it was the water pump, but it doesn't leak).

At this point, I didn't believe it was a chain issue itself so I installed a oil pressure gauge to diagnose the problem. When the oil warms up, it idles okay at 10 psi... but only revs to 20 psi (@5000 rpms). However, while it's warming up (it starts at 50-55 psi after the 0 psi chain rattle for 2-3 seconds), there is the whine and a gurgle sound. You rev it up and the gurgle and whine get more intense, when you let off, the whine and gurgle stop and the pressure IMMEDIATELY drops 10 psi.

I would think the low oil pressure was worn bearings except for the gurgle that's directly related to oil pressure.... Is it possible it's something other than bearings?

Engine has 160,000 miles on it. I autox it regularly but I'm very good about changing the dino oil every 3,000 miles.

Any thoughts? TIA!

Andy

[180fan]

have you checked the oil pump? There could be a blockage in the oil pick up. some more possibilities to consider

[maxq]

have you checked the oil pump?

My next step is to take both pans off. I just wanted to have an idea of what to look for before I get in there.

Quote »There could be a blockage in the oil pick up. [/quote]Wouldn't it be low during idle as well? I haven't ever taken the upper pan off but the lower pan was clean as a whistle 1000 miles ago. I thought the pickup looked clean as well... but not sure.

Good thinking, thanks!

[navysnail]

the tensioner is hydralic and operates off oil pressure, therefore if it was 0 psi, it would rattle. you need to look around under the oilpan and make sure your filter is good, it sounds like there may be alot of sludge in the pan or pickup

[s13sr20chris]

i advise you remove all drivebelts and try testing just to eliminate accessory noise. i also reccomend an oil analysis like blackstone labs or something. 20psi at 5000rpm is way too low. that motor is in trouble if you continue to drive hard on that kind of pressure. if you ever forsee an engine overhaul this may be the time for it(pending oil analysis results).

[maxq]

i advise you remove all drivebelts and try testing just to eliminate accessory noise.

But not for very long without the water pump, right?

Quote » i also reccomend an oil analysis like blackstone labs or something. [/quote]Problem... brand new oil. And I don't want to drive it any more before it's fixed.

Quote » that motor is in trouble if you continue to drive hard on that kind of pressure. if you ever forsee an engine overhaul this may be the time for it(pending oil analysis results).[/quote]I've driven it maybe a total of 400 street miles since the onset of the problem. Hopefullly, that's not too much. How many bearings (crank, rod) can I get to/see with the engine in the car?

Thanks!

[maxq]

Ok, the whine is not the accessories.

Sounds like it's coming from the oil pump/lower chain sprocket area.

It also doesn't make a peep until the engine develops oil pressure (3-4 seconds after startup). What could close up to allow pressure to build?

Andy

[s13sr20chris]

iv seen clogged pickups make some wierd noises. but you said yours is not clogged. you could try taking the pressure valve apart. its behind that big bolt on the front cover.

[maxq]

iv seen clogged pickups make some wierd noises. but you said yours is not clogged.

It wasn't clogged three months ago when I took the lower pan off... it's clogged now... with the shattered remants of the right-hand timing chain guide. Must've been 5-6 1/2x1/2" pieces of black ribbed plastic in the lower pan... three of which were stuck in the pickup.

I'm guessing the only way to replace the guide is to drop the engine and pull the front cover off?

[s13sr20chris]

yep

it can be done in the car but i would not reccomend it. reserve some down time and i will walk you through it.