Duratec low oil pressure - help needed to diagnose

[Shaun_E]

After all the issues I've had with the car, I thought I'd finally got it sorted with the replacement of the fuel pump but no.  

I drove the car at the weekend for the first time since the fuel pump was replaced and all seemed fine - car was running perfectly. Once warmed up and giving it some full throttle runs I noticed the oil pressure was lower than usual. The further I drove the lower it got until it dropped tp 7 or 8 psi. Raising the revs didn't seem to improve things. I headed straight home since by this point, nothing had gone bang and I assumed it was a failed pressure sender (supplied by Race Technology to go with the Dash 2 Pro I have fitted).

Today I have removed the sender and put a mechanical pressure gauge on and, unfortunately, it shows the RT sender is correct. Cold idle was showing about 22psi which began to drop as the car warmed up a bit and raising the revs caused the pressure to decrease - opposite to normal behaviour.

Normal oil pressure is closer to 30 psi at cold idle rising to approx 50psi at higher RPM. This drops to low 20s at hot idle and mid 40s at higher rpm. It's a 2.0 Ford Duratec fitted with a Raceline dry sump system with internal scavenge pump.

Any ideas? Oil pump, bearings? Is it going to be an engine out job and a trip to the engine builder?

The mechnical gauge is this one from DT. I have the sender mounted remotely with a hose from the oil filter housing - do I need to bleed the oil through before attaching the mechanical gauge?

 

[ScottR400D]

All I would say is that 30 psi at cold idle rising to approx 50psi at higher RPM seems low in any case. 

My dry sumped Duratec hot idles at around 2.5/3bar, 40/45psi and with more than a couple of thousand rpm shows at least 5bar, 75psi. 

Others will know better but that sounds like a pump issue to me. 

[John Vine]

#1  Could this be a problem with the oil pressure relief valve?  (Btw, your DT link shows a fuel pressure gauge.)

#2  For info, my R400D (wet sump) mechanical gauge shows cold idle = 65psi, hot idle = 30, hot @ 4K = 70-75.

[ETA:  That's using Comma Motorsport 5W/50]

JV

 

 

[Shaun_E]

Yes its a fuel pressure gauge but it's all I've got - it has the right range and thread fitting so I think it should work. It might not like hot oil but I've only tried it cold. Readings match those of the dash oil pressure sensor so no reason to suspect it isn't working.

Yes it could be PRV I guess - not sure where it is though. Pump is inside - needs front cover removing to see it. Any idea on how to check the PRV?

[7 wonders of the world]

how old is the DS set up, as there was a revision on the PRV, which now uses a longer plunger, this was introduced circa 10 years ago - 

Wetsump with OE pumps do run higher pressure, tuned engines run lower due to increases clearances and shells that come in a single grade .

What were your pressures before Shaun...... any odour from the oil.... fuel etc

[Shaun_E]

DS set-up was purchased early 2013 as part of a complete engine from Raceline.

Normal pressures were cold: 30 psi at idle /approx 50psi at higher RPM, hot: low 20s at idle/mid 40s at higher rpm - it has run like that since new and it's been rebuilt once in that time after a season racing. I am not concerned about the normal pressures since it has run (very successfully) like that for 10 years! 

I haven't noticed any odours from the oil but then again I haven't really checked. I had an oil analysis done last year and it came back clear of hydrocarbons and it's not been run much since then.

I've been chasing an issue with the car since last year and finally tracked it down to the fuel pump which has now been replaced. I guess it's remotely possible that running with the dodgy fuel pump has damaged something in the engine!

Question 1: can the oil pump be replaced with the engine in-situ? If I understand correctly, the Raceline DS set-up replaces the standard oil pump with a combined pressure/single stage scavenge pump - is that correct?
Question 2: is it worth trying that or should I just get the engine out and checked over properly? Can all the bearings be checked with the engine in-situ?

I can't get the engine our myself due to my back problems so will need to pay someone to do it.

 

[Shaun_E]

Car booked in at PGM for them to drop the sump and take a look.  

Symptoms do suggest a sticking PRV so lets hope that's all it is. I spoke to Raceline and although they've not seen any failures since the longer plunger was introduced, they agreed it was possible that it had somehow stuck open.

Answering my own questions.
1. Yes it's possible but not ideal since the front cover needs to come off the engine.
2. Easy enough to remove the bearing caps once the sump is off so they will be checked.

Let's see what Andy finds. If it's not the pump then it's engine out time.

[Shaun_E]

Engine is now out and with the engine builder so we should find out soon enough.When PGM drained the oil it had a metallic sheen to it hence going straight to engine strip down rather than just replacing the oil pump.

I just stripped the Laminova heat exchanger and the core has lots of tiny pieces of metal in it - that doesn't bode well especially as they are magnetic!