Kevin Michael

Today I decide to drive it being it is my day off. 3 miles into my ride I decide to wind her up. I hear a muffled pop and she has less than half her power! The exhaust sounds way strange as well and my oil pressure started reading 1.5 bar idle and 4 at 4000rpm. No smoke, leaks, stalling stumbling or anything it just has no power and the exhaust sounds very untuned for lack of a better description. Oil level is fine but the pressure is reading low.
Any ideas? What a miserable day off!
Kevin

Kevin Michael

One more thing, when revved there is a light clanking metallic noise coming from the rear pass. side of engine somewhere. Thanks.

S4-on-your-back-door

tb jumped?

heinrich

Well kevin, I was going to say it sounded like a coil wire or other loose connector but the light clanking metallic sound ... use a screwdriver and check it .... run the engine as little as possible. Before starting again, check the usual suspects, spark; fuel; rotors; wires; dipstick; coolant, belts.

svp928

Pop a hose on the S/C? Wouldn't explain the oil pressure...

Mike Simard

Wild guess here...
Your oil pump picked up a piece of debris and this momentarily seized it. The timing belt then jumps and the pump resumes pumping although now damaged puts out less oil and now your timing is off.

the flyin' scotsman

Can you tell if its running on all 8?

Exhaust manifold temp will give a very quick indication. If not all 8 then do you have spark on all plugs?

MAF issue caused 'limp home' mode and she's only firing on 4?

Jfrahm

I'd be worried about a timing chain given the noise and 1/2 power. Is the centermost cam cover bolt loose on the affected side?

Kevin Michael

Everything so far from everyone has been checked and ok'd. The engine has had time to cool for 2hrs with the help of a snail fan. Here's the really odd part. I just restarted it and the oil pressure is 3 bar with 5 bar coming at 2000 rpms. Perfectly normal. But as the engine runs the exhaust slowly starts sounding bad again and the oil pressure slowly drops to 1.5 bar. This takes about 20 minutes to happen. I am cooling it down again so I can pull the timing covers and check the alignment. What Mike Simard said was what I have been thinking because The brand new Vortech head unit blew its bearings about 2 months ago. Tim Murphy stood behind it and now I have a new one which is operating fine. But maybe a chunk of something finally found its way to the pump? Oddly when cool it acts perfectly then the symptoms arise.
Kevin

Charley B

After warm up and the poor running condition ensues, how does it act when you shut it off and attempt to start again. Rough (slow) start or normal start?

Tony

Drain your oil...and hope for nothing stuck to the magnet.

Kevin Michael

Normal start.

ew928

What does a clogged rattliing cat sound like?
Do you still have the dual factory cat, KM?

Hoping for something external rather than internal to motor prob.

heinrich

Cats yes, but the oil pressure ... not cat-related.

Bill Ball

With the engine warm/hot, 1.5 bar at idle is on the low end of normal. 4 bar at 4000 is low, but could be considered within spec. Are you sure this is a change from before? Your observation of the pressure when cold or cooled down is normal, as you noted, and I'm not sure the hot pressure is a problem. Now, if you were just running Amsoil, you'd have plenty of pressure!

Anyway, the oil pressure observations may not be significant. The power loss in a supercharged car usually means you should look at the SC first, unless you blew a head gasket. You aren't running that much boost, are you? Anyway, you'd know that by other symptoms. The blow-off valve could be malfunctioning, but that would be noticeable hot or cold.

I'm having a hard time coming up with anything that would change the exhaust note and power as the car warms up other than an exhaust problem.