Brain teaser for a Tuesday morning.

I have been a mechanic for 30 years and have made my share of mistakes, but this was one I will not forget.
I was preparing my race car for the Mid Ohio club race last week and started the car to check for any leaks . I noticed that the timing chain tensioners took longer than normal to pump up. looking at the oil pressure gauge it was only at 3 bar with the oil cold. After the engine warmed up it would only go to a little over 2 bar at 4000 RPM. At idle the oil pressure was a normal 1.2bar. I removed the oil pump and did not find anything abnormal.

This is a freshly rebuilt engine with 1 hour on the dyno and 4 20 minute track sessions.

What do you think the problem was, I will post the fix to the problum with pictures later today.

 

1. If a stock oil filter canister - weak or stuck open bypass valve.
2. Wrong oil weight.
3. There was the DIY guy that tried to drain his oil from the oil pump bypass valve and dropped the spring in the oil drain pan. Reinstalled without it and viola...no oil pressure.

 

My first guess was a broken bypass spring. Oil pump was not the problum. A weak oil filter bypass will still deliver the correct oil pressure.
To guess the problem you have to think like Homer Simpson DOH.
The cause of the problem was something every DIYer has done to there car.

 

Sorry, cannot think like Homer Simpson. I did assume that your oil level was where it should be, and if there is nothing wrong with the oil pump, and thus it was operating correctly, then where was all the oil pressure going? Hole in the block? Or, a faulty oil pressure sender unit? You didn't say it was spewing oil all over from a massive leak, say at the filter or oil cooler. Oh Well, end of my guesses so just have to wait to find out.

 

Oil Level spot on, No problem with the oil pressure gauge, Not spewing oil, the engine is perfectly fine after the fix without removing the engine.

 

Forgot to put the dipstick back in?

 

You didn't put the cap back on the oil fill tube?

 

Foil from an oil bottle partially covering the mesh on the pickup tube.

 

Oh that's a good one!

 

We have a winner good job, The foil from a oil bottle was blocking the pickup
It was ok on the dyno, ok during the test sessions. but showed up when back at the shop.

As a profession This mistake should not have happened and I am fortunate to not lose a $20,000 engine. A lot of work went into this motor and to spin a rod would be very disappointing.

 

AWWWW YEAH.

Amazing how something worth a fraction of a cent has the capability to burn $20K.

 

Foiled again!

 

I always wonder why oil companies package the product this way. It's almost impossible to get all of the foil off the bottle without tearing it and leaving a little behind.

Always concerned I'll do the same so I try to be extra careful but I wish there was a better way to seal those bottles from the factory.

 

Motul does it differently.

 

Puncture the foil, dont tear it.