Crank seal in front cover cause low startup oil pressure?

[d1driver]

98 D1. Definitely not a rookie around here.

Just noticed the seal started leaking lately just behind the crank pulley. When I start the truck, it takes a little while for the pressure to build. Maybe 15-20 seconds before light goes out. When it comes up, it goes to around 45psi. I have a mechanical pressure gauge installed and it appears to work as it should, due to once the oil light goes out, the gauge shoots up.

I have been through this thing many times. Everything has been cleaned, replaced, etc. Even that seal was replaced less than 10k miles ago.

This thing runs 45psi on the highway all day long and never below 20psi at idle. These dry starts are just making me worry. Lifters tap slightly during the startup too, which I do not like.

I run Rotella in it with the Napa gold filter.

Will that small seal leak cause dry startup? It is barely leaking. With new oil pump gears, clean screen and pan, and absolutely no oil leaks anywhere else, what the heck should I look at? Its been a while since my last oil change, but the oil still looks clean when I check it. This truck doesn't get driven much anymore. Less than 2k miles in the last year.

 

[distrovol]

The pick up pipe o-ring, bad (or cheap) oil filter, and pressure relief piston stuck come to mind. Atmosphere seems to be getting into the lube system when off, is there a correlation to time shut down and the problem happening or not? The seal should not cause the system to lose prime from my recollection of having it appart.

 

[d1driver]

The front cover was steam cleaned thoroughly and the pressure relief valve cleaned and functioned as it should. Pick up tube cleaned and reinstalled less than 2k miles ago. The oil filter is Napa Gold.

Once the truck is warm, everything is fine. Once it sits overnight, I get a dry start again.

 

[riceybean]

I would throw another filter on just be sure, you could have a defective by-pass/drain back valve. Cheap and easy thing to check.

 

[distrovol]

I was speaking to the o-ring where the pick-up pipe attaches to the timing cover. If it is missing, faulty, or pinched during installation all could look well but you will lose system prime.

 

[listerdiesel]

The timing cover oil seal doesn't really have much to do with the oil pressure, it's just there to keep cr*p out and oil in, it isn't part of the pressure or suction side.

The loss of start-up oil is down to the residual oil in the pickup tube running back to the sump overnight, and can only do that if air can get into the pump body via wear in the gear set or the alloy housing it runs in.

Gear to housing wear is obviously going to get worse with age, and it's the main housing that seems to wear, rather than the steel cover plate.

If you park facing downhill, you may find it eases the problem, as will keeping the oil level right up to the mark.

Peter


Peter

 

[riceybean]

I was speaking to the o-ring where the pick-up pipe attaches to the timing cover. If it is missing, faulty, or pinched during installation all could look well but you will lose system prime.

This is good to know, never thought of that. Its about time to drop my pan anyway.

 

[d1driver]

The oil pickup tube on a D1 goes straight up into the bottom of the block....not to the timing cover. If my memory serves me correctly, I believe it had a little gasket on it which I replaced.

Maybe time for me to drop the pan again when I change the oil and check the pickup tube once again. Too bad I use Right Stuff and it is a pain in the arse to get it all off.

 

[forcefed44]

This is nice to know.. I'm expiriencing the same leak on the front of my truck from the seal area.. When the truck is shut off it drips on to the panhard rod lightly and then it makes a 6 inch stain on the floor then stops and that is the extent of the leak.. I checked all the oil lines, cleaned the covers and pans...

Unfortunately I'm overseas right now to fix..

Chris

 

[jims95]

Remove the pressure relief valve and clean it first. A little debris picked up somewhere in the oil system can cause the relief valve to malfunction. Some debris might have been trapped in a passage of the front timing cover when you steam cleaned it, and the detergent in the oil lossened it over time.

This will be the easiest and quickest thing to check. If this is the problem you won't need to remove the oil pan that you put on with Right stuff.