Cat C-9 High Oil Pressure At Startup

[2stroker]

I have a C-9 2005 motor in a 2006 Country Coach. Has anyone had oil pressure that has pegged the dash gauge at 100lbs psi on a cold start. Looking at my Silverleaf at cold start the pressure is 127lbs so I use the block heater for about 2hrs to get the pressure under 100 on a cool day.

After it warms up going down the road it runs 45-48psi at 1600rpm and idles 25-30psi. I think most coaches have 2 sending units, 1 that the coach builder installed and 1 that the motor builder installed. I have looked at both coming from 2 different places and they both read the same.

Country Coach oil pressure sender 0-100 psi VDO and Cat installed one that the ECM reads (Silverleaf) and they both move together. The one on the dash will stay at 100psi until the oil gets warm and then they both move down together. Cat tech say, cold startup pressure should be around 87psi above 100psi could blow the oil filter apart. 

So my question is has anyone replace the oil pump to solve this problem or replace the relief valve in the filter head. I have had this problem as long as I have had the coach going on 4 years. 

Thanks for any help on this.
2stroker

[wolfe10]

2stroker,

Welcome to the FMCA Forum.

What weight oil are you using?

Have you consulted the Caterpillar RV Hotline for their insights? They can be reached M-F at 877 777-3126. Have your engine serial number handy when you call them.

[dickandlois]

2stroker, Welcome !

Just curious as to what the oil pressure runs at idle when the engine is Hot ?

Rich.

[CarlAda]

Welcome to the forum, Floyd

[wildebill308]

Welcome to the forum. I don't think it will hurt your filter if you are using a quality filter. I am wondering what oil are you using? 

Bill

[2stroker]

Good morning CarlAda, hope your repairs are going well.

I use Cat oil filters 1R1808, Mobil Delvac 1300 15w40.   Idle hot 25-30psi

Have call the Cat Hot Line No Help.

Called Peterson Cat, No Help.

Sometimes high oil pressure, not so good.  http://forums.cat.com/t5/Maintenance/C9-Engine-that-keeps-blowing-oil-filter-seals/td-p/4974

Floyd

[obedb]

Drove diesel powered trucks for 46 years or so. Have never seen anything like what you mention. Maybe jLeamont can chime in with his opinion.

[obedb]

Your cruising pressure is pretty much normal for today's engines. I remember when cruising pressures were higher maybe 60 psi or close, but that stopped a while ago. Never liked the lower pressure, but I vaguely remember increasing flow in the new engines while lowering pressure  through engineering changes increased mpg somewhat. If you have been running those high cold idle temps for four years with no damage, good for you. When in a park. I turn the block heater on the night before. Takes very little time to warm up and start moving by doing that.

[2stroker]

 Thanks guys for your replies.  I know I have a cold problem start just don't want to pick the wrong one. I have just came across one person with a C-9 that has had this problem in a coach and he had the oil pump replaced Peterson Cat in California. He had cold start pressure of 130psi now 85psi.

 Pump cost $365 + pan set and 4 to 6 hrs shop time.

Floyd

[wildebill308]

12 hours ago, 2stroker said:

 Thanks guys for your replies.  I know I have a cold problem start just don't want to pick the wrong one. I have just came across one person with a C-9 that has had this problem in a coach and he had the oil pump replaced Peterson Cat in California. He had cold start pressure of 130psi now 85psi.

 Pump cost $365 + pan set and 4 to 6 hrs shop time.

Floyd

My thought is yes it is higher than what Cat specks but you aren't having any problem with it blowing the seal on the oil filter. Before I spent 600-800 dollars I would try running a oil like Rotella T-6 that is a 5-40 oil. and run the block heater for a couple hours before starting when it is cold.

Bill

[ziggyh]

I also had that problem with the oil pressure spilking high ang low on startup when cold, the cause I had was the regulator valve in the oil pump sticking because the valve was scored.  The pump had 900 hours on it.  The oil filter o-ring will blow out with high pressures over 130

[wolfe10]

Ziggyh,

Is that spring and regulator valve available separately, or only with a complete oil pump?

And, what was your cold oil pressure after the replacement?

[2stroker]

ziggyh thanks for showing.  I don't have a low pressure anytime at startup just high oil pressure. I have been thinking of switching to Rotella T-6 5w40 or Delo 400 LE Synthetic SAE 5W-40. I'm just getting tired of getting out the extension cord to warm it up even on a warm day at 60deg. I don't like switching brands of oil all the time.

I just got my mid-drain oil sample back and it is clean. With 2200mi  iron 6  copper 2 chromium 0 aluminum 2 nickel 0   Thanks everyone for your input.

Floyd

[ziggyh]

Brett, I didn't check if the valve and spring was available separately. The bore in the pump looked like new as well as the rest of it, I didn't bother to do any wear measurements on the pump. The pump body is aluminum.  I had purchased a reman pump before I took the old one out and then inspected the old pump before returning it for the core credit.

With the old pump my oil pressure cold would intermittently spike to 130-150 on a mechanical test gauge and then drop to a few pounds for a second and then return to normal.

With the new pump on cold startup and using cat 10w-30 deo at 30 deg f the pressure is 90-100 psi, I have since switched to 10w-30 t5 and the cold pressure is the same.

[ziggyh]

2stroker, you mentioned the relief valve in the filter head, there are 2 valves in the filter head, one is a by pass for the oil filter should it become restricted and the other is a by pass for the oil cooler, the valve in the pump controles the pressure.

[obedb]

Once again motorhomes puzzle me. The OP mentioned contacting Cat Hotline and a Cat dealer with no help from either, therefore,  never gave the oil pump another thought. In hundreds of thousands of miles on an engine I have never had an oil pump cause a problem. If the oil pump can't lubricate itself and work properly in the process, then what hope do we have that it will protect the engine? Bizarre. Especially because it is Caterpillar. At one time, the "gold standard." 

Sometimes, I miss our travel trailer.

[2stroker]

I don't mind hooking up a extension cord (gets old) but when you are in a park and it is 50 or 60degs outside you look kind of stupid heating a motor.

I have called the Cat Hot line before with good outcome but this time it was a joke. Peterson Cat has worked on my motor before, 2 times and I would have thought the high oil pressure would have been flagged at that time because they printed out 5 pages from the ECM lot of it blank but still cost.

[wildebill308]

12 minutes ago, 2stroker said:

I don't mind hooking up a extension cord (gets old) but when you are in a park and it is 50 or 60degs outside you look kind of stupid heating a motor.

I have called the Cat Hot line before with good outcome but this time it was a joke. Peterson Cat has worked on my motor before, 2 times and I would have thought the high oil pressure would have been flagged at that time because they printed out 5 pages from the ECM lot of it blank but still cost.

If you are in a park plugged in why do you need to run a extension cord?

Bill

[2stroker]

Bill

 On mine (old school) you have to open the back door and plug into the line to the block heater. I know some you just go to the bedroom and flip a switch.  I have the same thing on my Ford PSD and Ford Edge. 

Floyd

[jleamont]

2stroker, Ziggyh hit the nail on the head.

I'd bet your oil pressure relief valve is sticking, I have seem a few over they years scored like the one in the photo, it doesn't take much for them to bind under pressure in their bore. I have also seen the reverse side where the snap ring fails and the valve falls out. Your need to get that fixed ASAP.

Lucky for you the OEM oil filter housings are usually thicker than most aftermarket. I have seen aftermarket filters detonate before from what you are describing. Some aftermarket filters are so thin the oil filter wrench scratch upon installation causing leaks in a few hundred miles.

Do your best to warm the oil prior to departing, from your warm engine oil pressure description it is doing its job when the oil thins out and allowing oil to bypass the valve, so that's a huge plus.

Some engines they are located just above the oil filter, in the front cover near the harmonic balancer and others they are internal to the oil pump. Depending on the design will determine how it is to be replaced.

[2stroker]

OK, so I don't have a high to low back to high oil pressure jumping around, just high then coming down as it gets warmed up.

Need a little help guys.  I'm going to switch oil from Mobil 15w40 to a 5w40 Full Synthetic and add this to the pan.
Engine Heater Oil Pan Tank Heater Pad Heater 1000 Watt 6 x 10.75 110/120 Volt | eBay
If I take it in to Cat the cost will be $1000 to $1300 parts and labor (I think) maybe more, so here are the choices, what would you pick.

1. Delo 400LE 5w40 
2. Mobil Tubo Diesel Truck 5w40 
3. Rotella T6 5w40

Floyd

[wildebill308]

I am running T6 now and my oil samples are coming back excellent. Also if you buy before the first there is a $5.00 a gallon rebate.

http://rotella.shell.com/coupons-rebates-and-sweepstakes/save-5-per-gallon.html

I have run the Mobil 1 Turbo Diesel Truck and had good results with it as well.

Bill

[2stroker]

Bill

Thanks for the info, looks like it will be T6 and the rebate form.

Floyd

[2stroker]

Update

  Just got home from Peterson Cat with my coach. They installed a reman pump and Cat 15w40 oil. Now my cold start is 85psi and 101psi at high idle running 55mph oil pressure runs 50 to 55psi and idles at 20psi.  They pulled the valve that zigghy showed in his posting and it looked just like that one. They also pull the valve on the filter head and it was OK. When I change oil next time I will be running 5w40 syn because of the HEUI pump and injectors.

 Thanks everyone for your input and to ziggyh for posting the picture, it helped a lot.

Floyd

[wildebill308]

Glad you got it sorted out.

Bill