High Oil Pressure and FMS

[turboshad]

I've always had high oil pressure in the 2.4 but never thought it was much of a problem. I get 100psi cold and about 35psi at idle hot. It easily rises 15psi per 1000 rpm. I've also had a pesky oil leak for a while which drives me nuts because it makes everything I try so hard to keep clean dirty. I wasn't ever able to find the leak but with the engine out I pulled the front pully to find it is definately coming from the front main seal. Any one else seeing this problem? Is there anything I can do to drop the oil pressure upper limit? I am running DCR billet gears so I don't know if that has anything to do with it. Just curiuos what others are experiencing. Thx.

[t3rse]

My oil pressure was always a bit high. I have a modified 2.2/2.5 oil restrictor in place and had to restrict oil to the turbo.

[turbovanman²]

Is the front seal damaged???? I can't see how having high oil pressure will cause a leak at the seal.
Is there room to make and put a slinger behind the seal?

[Speedeuphoria]

I thought the DCR gears were slightly smaller and had relief notches which I thought would slightly lower the oil psi a little. Also I thought there is a bypass in it so it wouldnt go over like 80psi, thats what mine seems to bounce off of at cold idle(stock srt pump w/ ported/polished ports)

[turboshad]

My oil pressure was always a bit high. I have a modified 2.2/2.5 oil restrictor in place and had to restrict oil to the turbo.

Ya, I have a restrictor in the block for the head that I welded and redrilled but that doesn't help the FMS. My turbo has been fine.

Is the front seal damaged???? I can't see how having high oil pressure will cause a leak at the seal.
Is there room to make and put a slinger behind the seal?

The oil pump on the 2.4 is connected to the front of the crank. The FMS is in the oil pump housing itself. With excess pressure the oil could force itself around the pump gears and into the FMS area. These are obviously broken gears but you can see where the oil could push through.

I thought the DCR gears were slightly smaller and had relief notches which I thought would slightly lower the oil psi a little. Also I thought there is a bypass in it so it wouldnt go over like 80psi, thats what mine seems to bounce off of at cold idle(stock srt pump w/ ported/polished ports)

I haven't taken a close look at the pump, so maybe there is a bypass I can get another spring for. I will have to look into it.

[turbovanman²]

The oil pump on the 2.4 is connected to the front of the crank. The FMS is in the oil pump housing itself. With excess pressure the oil could force itself around the pump gears and into the FMS area. These are obviously broken gears but you can see where the oil could push through.







I haven't taken a close look at the pump, so maybe there is a bypass I can get another spring for. I will have to look into it.

I know where the pump is, just wasn't sure if there was any room for a slinger. Other vehicles have room for one, IE GM's 3.8L. Is JT having front seal issues?

Having the oil come past the side plate and blow out of the seal seems a bit far fetched. What brand of seal did you use? I know in my engine, aftermarket makes a single lip seal and I can NEVER get that sucker to seal, used Mopars double lip design, fixed.

[Speedeuphoria]

I haven't taken a close look at the pump, so maybe there is a bypass I can get another spring for. I will have to look into it.

yeah I'm pretty sure the bypass spring is visible in this pic(circled in red now). I believe there is a freeze plug in the bottom of the housing that needs to come out to get to the spring.


Just not sure it should be needed?? Is that whole pump from DCR?? or just the gears?? I assume its just the gears and I would call or PM DCR to ask about it and see what they say.

For the record I have a modded block restrictor and 2.7Rockers and restrictor to turbo also.

BTW what weight oil are you running?

If you havent already, when you take the pump off port all the passages into the pan also(on the SRT pan you have to take out the large hex plugs to get in there good) and oil filter adapter. The only thing I forgot to do is drill out the oil drains in the head and champher them

[t3rse]

Ya, I have a restrictor in the block for the head that I welded and redrilled but that doesn't help the FMS. My turbo has been fine.

If anything the restrictor would raise oil pressure to the bottom end some...I've had no FMS leak issues.

[BadAssPerformance]

My oil pressure is high too.... pics of the restrictor?

[Speedeuphoria]

Its the same old 2.2/2.5 oil restricter that goes in the block. Still ~$3 from the dealer

Just from neons.org you can weld the hole shut and redrill it out to a smaller size so it does the same thing as the "DCR oil modifier"

Basically the old head gaskets had a restricter built in but the hole was still large and with the MLS and diff manufacturers the hole size can vary, IIIRC its normally around .180" and the stock 2.2/2.5 resticter is like ~.140"

[turbovanman²]

But if you reduce the size of the restrictor, your oil pressure should go up even more, the opposite of what you guys are after.

[t3rse]

Correct: my point was that I was seeing 90 psi on the block when it was 45*F outside until the car was thoroughly warm and I've never had FMS issues.

But it would be nice to be able to lower the oil pressure easily....

[Speedeuphoria]

But if you reduce the size of the restrictor, your oil pressure should go up even more, the opposite of what you guys are after.

right but I have the restricter modded and see 80psi max

also btw thats with 10w30 and oil press sensor in pan

[turboshad]

I guess the restrictor is a bit of a catch 22. Too much oil in the head or higher pressure. Like Speed said, it is just the stock 2.2/2.5 block restrictor with the hole welded shut and redrilled. I can't remeber what I driiled it out to but some time back I coersed the size that Speed used out of him and went slightly larger. I do see that I seem to be the only one with FMS issues which is good to hear. That means it may just be a bad seal.

Thanks for the tip on the Mopar seal Simon. I know the one I have now is aftermarket so I will change that for sure. The engine is almost completely apart now so I will be going over everything anyway and replacing all the seals.

[turbovanman²]

Correct: my point was that I was seeing 90 psi on the block when it was 45*F outside until the car was thoroughly warm and I've never had FMS issues.

But it would be nice to be able to lower the oil pressure easily....

Ok, just making sure we are on the same page,

If you want to lower the oil pressure, then you have to make the relief valve spring softer or shorter to it opens earlier.

[turboshad]

If you want to lower the oil pressure, then you have to make the relief valve spring softer or shorter to it opens earlier.

Ya, I don't think that's something I want to be experimenting with. 1) It's hard to change once the engine is assembled. 2) If I get it wrong it could be bad.

[t3rse]

No kidding! I was thinking something a little more novel like an external relieve valve. One could put a relief valve on the passage going to the oil filter in the pan and just dump the excess back into the pan.

[turboshad]

Well I'm pretty sure I found the problem. I got the engine completely torn down today which gave me a better look at things behind the crank gear. I found a mopar double seal and the back of the crank gear was clean. This was confusing since it should be quite dirty if the FMS was leaking. There was still lots of sludge around the bottom where the timing belt rides though. Hmmmm.....not to many answers. Well I am going to Houston next week so I was looking to see what I could get from Modern Performance for the rebuild. While browsing the site I found a "Mopar OEM Front Cover Oil Inlet seal 03-05 SRT4". What the heck is that? Well I pulled up a pic of an SRT4 pump on srtforums and what do ya know. Guess what I was missing. I never even knew there was a seal for the pressure side, I only knew about the pickup. Looking at it now I was a bit dumb not to notice an o-ring counter bore. So this whole time I was sealing the pressure side of my pump with anerobic. That of course sprung a little crack which was letting oil seap out between the block and pump but since things were torqued it wasn't enough to ever let the oil pressure drop. I am quite excited to have found it and hopefully have a leak free engine , yet also a little embarassed that I didn't know how to put it together the first time.

Here is the O-ring I was missing. Top right.

[Speedeuphoria]

wow surprised it held up to the pressure but glad you found it

[turbovanman²]

You should be embarassed, EVERYONE knows about that seal, and you call yourself an engineer.

Glad you figured it out.