Guys,

Just returned from Shawn Church after having my motor rebuilt. The car is an 06 AP2 and was rebuilt by Laskey with a portflow head. I have the high boost Kraftwerks supercharger and a PWR radiator with the built in oil cooler. Everything was going great until the car started dropping out of VTEC at about 7000 rpm when the oil got hot. When it was cooler she would run right up to 8K and made 424 to the wheels. We hit that number 3 times then it started falling out of VTEC. When I brought it in I had some pretty cheap oil for the break in procedure but it turned out to be way too thin even at 10W/30. The thought was that after the oil heated up it lost enough viscosity to drop the pins. After changing to a better quality 10W/40 we thought the problem was nailed. After the first 3 runs Shawn Church was not convinced so ran it again. It did fine but on the next run it fell off at 7K. We all suspect an oil pressure problem but I'm not sure where to start. I ran an AEM wide band oil pressure gauge to the remote filter and was reading 90+ psi (100+ when the oil was cooler). I plan to move it to the sandwich at the original filter location to see if I am getting lower pressure at the block. If so, would relocating the remote filter closer to the original location give me better pressure since the hoses would be shorter? Also, has anyone had a problem with the PWR radiator/oil cooler system losing oil pressure. On a side note, the guys at Church are first class. They went way overboard helping me and stayed way past i would have ever expected them to. No matter what comes up, they just jump in and handle it. Great experience. I was there until 9pm and Shawn would only let me take the car when he was sure it was safe. We talked about some possible causes of the drop in VTEC but I need to find out what is going on, fix it then take it back to him to confirm. Before anyone asks about the cat, I have a Berk test pipe on the car so that's not the issue. We tested the solenoid and confirmed all pins were correctly positioned. Also, the filter at the solenoid is clean.

Thanks,

Steve

 

does it fall out of vtec at 7k rpm or does it hit the rev limiter at 7k rpms. Reason I ask is that the ecu will cut rpms at 7k when the engine temps are not what it wants to see (happened to me today). It is odd that your issue does it right at 7k, thus the reason for my question.

Have you made significant changes to the cooling system ?, if so perhaps they were too good and the ecu is having issues with that and cutting power. If the issue is occurring right at 7k I think it is ecu related and it is stepping in based on some parameter that it doesn't like. If it isn't cooling related, there might be other parameters that can trigger the ecu in cutting vtec, they might be listed in the service manual ?.

 

Define "dropping out of VTEC". Is the power falling off, or are you reading data off of a scanner that can read the VTEC status on/off?

Has it been 100% determined that the engine is running to redline, from 7k to 8k, on the primary cam lobe? (This would show a big loss in power starting at 7k)

Dropping out of VTEC means the pins are not holding the rockers together in HIGH-CAM mode. Is this the case?

 

x2

Their will be a HUGE power drop if it does in fact drop out of VTEC at that high of an RPM.

 

At 7K it is not hitting the rev limiter. You can see on the dyno graph a large fall off in power at 7K and also hear it. In earlier runs, once the car did that, the next run was even worse- it would just touch VTEC and fall out. It was really bad on the oil I had in the car when I brought it in and better with the 10W/40. I am running a different cooling system (PWR with a built in oil cooler) which I'm beginning to suspect. It seems plenty of guys have added hose, remote filters and oil coolers without issue. Is it possible to put on the sandwich incorrectly causing a drop in pressure after the filter?

To more specifically answer Billman's question, once it fell off VTEC Shawn was off the throttle so I don't think he ever took it to redline unless the VTEC was fully engaged. The day before we did have a problem and could not get the car to engage the high cam at all but that was due to a missing pin. We took it apart, replaced the pin and had VTEC after that. The next day the pressure issue raised it's head

To H22's statement- yes, there was a huge loss of power, it was like falling off a wall

When the oil was cool, it very strong all the way to redline without a hiccup. As I said earlier, we did the 4 times on fresh oil, the 5the run was when it fell off.

 

Should I post this in the forced induction forum?

 

Moving

 

I'll check over there but I have a similar problem with a stock motor but in a kit car.

Will run up to 8 grand with the VTEC 3 or 4 times and then cut out very similar to above ... get VSS malfunction code and misfire code

 

Do you have a CEL ?

 

Did you try to bypass the oil cooling system?

How many quarts to fill you system/engine?

J