So just tore apart my engine on my 2011 g37 to install jet c2 cams. Normally I put 5 quarts of oil in my car but because I lost so much in the tear down I put about 5 and a half. After starting the car and letting it run for about 10 minutes I let it sit for a bit, then checked oil. The dipstick says it’s low even after adding more. So to avoid overfilling it I went ahead and added just another quarter of a quart. Took it to Houston to get it tuned and admin tuning says we have low oil pressure. Is it possible I don’t have enough oil in it? I replaced the o rings on the gallery’s and replaced the gallery gasket. So why does it still seem like I have low oil pressure?

 

Unless you have a gauge and are able to notice the actual pressures and your dipstick is reading where it's supposed to then you might be having cam issues.

How did admin determine if you had low oil psi? by actual gauge or by a p0524 code or other oil pressure codes?

If it was by codes then this means that the VTC is not receiving the right pressures and triggers a light and doesnt let the cams adjust

If it was an actual gauge can you post numbers at idle, 1k, 2k, 3k RPM?

 

Ok so admintuning never said it was low oil pressure, just a loss of power, and low oil pressure was the most likely reason. After doing an oil pressure test, I’ve concluded oil pressure checks out and is ok. Moncef also said that the cam install went fine, as he sees no issue related to timing, and the cams were doing fine. Next option is to do a leakdown test.

 

Weird that he would say loss of power due to oil pressure but timing checks out. Loss of oil pressure would send the VTCs to the moon and back.
Was this an issue that started right after the cams were installed or something that happened during tuning?

 

well kinda both. There of course was no issue before the cam install. But the power progressively got weaker after each pull on the dyno. I almost doubt it’s a stuck open valve, if it was 8000 rpm on the dyno would have screwed up a valve easily. Do you believe carbon buildup could cause that much loss in power.

 

Here’s a dyno graph to better understand the power loss.

 

Pretty weird results for sure.
Things to note are:
25 whp loss with each pull which is pretty significant
This much of a loss would have made itself visible/noticeable
This happened after cam install
Graph simulates a boost by gear dyno just oppositely
Graph simulates previous run just at lower power but very similar graphs
Lost 50WHP and 60TQ.
Loss of compression could simulate this as well

I gave JWT a call and they're as baffled as we are.

You'll need to do some additional data acquisition.

An oil pressure test will confirm if the gasket broke which could explain, it is possible that it broke after the first run and just didnt advance the cams as supposed to and the last pull killed it which makes the VTC move even less.
A compression test will confirm that you didnt mess anything up internally
A leak down test will confirm that if it is a compression loss, where is it coming from.

Very interested in what could have caused this, keep us updated.