J

jrod2550

New Member

• Aug 15, 2023

• #1

Hi!

First time P38 owner and newbie here, so I really appreciate the help. I have a 1998 P38 4.6 leaking oil consistently. Despite this, no major issues driving. I have recently replaced the tensioner pulley as well, but no other big issues.

Initially, the undercarriage had oil EVERYWHERE. Dried, old, new, you name it... It only visibly leaked after driving. If it sat for a few days, it will not leak on it's own. I have been adding oil everynow and then as a hold over. It's not driven as a daily driver so I estimate I have added 1-2 liters for ~1,500 km

I changed oil + oil filter, all without issue. I then cleaned it off with brake cleaner, scrubbed, pressure washed, etc so it was clean. With hopes of spotting the leak.

The picture below is from the very next morning and maybe 15 minutes of driving. It seems the leak is coming from somehwer eat gearbox (?) or above it.

So: my question is where do I begin? Any initial ideas or things I should absolutely check/change?

THANK YOU

 

kermit_rr

Very

Full Member

• Aug 15, 2023

• #2

Is that oil on the starter motor?
Check the rocker cover gaskets, if the covers are even slightly loose the gaskets can come off and leak everywhere. They clip on the the rocket covers, so if you don't see the rubber lip then they will leak. Hard to see at the back so feel for it

 

Montyjohn

Well-Known Member

• Aug 15, 2023

• #3

My money would be on the rear main seal unless there's visible oil higher up the engine. What grade oil are you using. If it is the rear main seal, then using 20W-50 won't hurt and may slow it down enough to live with whilst you find time to sort it.

 

kermit_rr

Very

Full Member

• Aug 15, 2023

• #4

should be using 20/50 anyways on the V8, the thinner stuff was purely to help get emissions down
valvoline 20/50 every time for me, with added ZDDP to look after your cams

 

J

jrod2550

New Member

• Aug 15, 2023

• #5

kermit_rr said:

Is that oil on the starter motor?
Check the rocker cover gaskets, if the covers are even slightly loose the gaskets can come off and leak everywhere. They clip on the the rocket covers, so if you don't see the rubber lip then they will leak. Hard to see at the back so feel for it

Click to expand...

Thanks, yes, looks like some on the starter motor as well. I can't say for sure, but it does seem to being coming from top side of engine and leaking down to where you see it on gear box.

 

J

jrod2550

New Member

• Aug 15, 2023

• #6

kermit_rr said:

should be using 20/50 anyways on the V8, the thinner stuff was purely to help get emissions down
valvoline 20/50 every time for me, with added ZDDP to look after your cams

Click to expand...

just refilled with 15-40, but this is good advice, especially given situation

 

J

jrod2550

New Member

• Aug 15, 2023

• #7

It's difficult to get a good picture. but here are some more:

 

marjon

Well-Known Member

Full Member

• Aug 15, 2023

• #8

Could be the valley gasket at the back if it seems to be both sides evenly.

J

 

kermit_rr

Very

Full Member

• Aug 15, 2023

• #9

marjon said:

Could be the valley gasket at the back if it seems to be both sides evenly.

J

Click to expand...

could be though if theres a lot of oil, more likely to be rocker gasket.. in my opinion

 

marjon

Well-Known Member

Full Member

• Aug 15, 2023

• #10

jrod2550 said:

The picture below is from the very next morning and maybe 15 minutes of driving. It seems the leak is coming from somehwer eat gearbox (?) or above it.

Click to expand...

The problem is when driving the airflow under car/bonnet will move oil all over the place.

Clean it off and just run it on the drive with the bonnet up to try and identify where the oil first appears.

J

 

N

nigelbb

Well-Known Member

• Aug 16, 2023

• #11

kermit_rr said:

should be using 20/50 anyways on the V8, the thinner stuff was purely to help get emissions down
valvoline 20/50 every time for me, with added ZDDP to look after your cams

Click to expand...

The recommendation I got from V8 Developments after they rebuilt my engine was an oil change with Valvoline VR1 Racing 20w-50 after 1,000 miles then every 5,000 miles after that.

 

kermit_rr

Very

Full Member

• Aug 16, 2023

• #12

nigelbb said:

The recommendation I got from V8 Developments after they rebuilt my engine was an oil change with Valvoline VR1 Racing 20w-50 after 1,000 miles then every 5,000 miles after that.

Click to expand...

We can't both be wrong

 

J

jrod2550

New Member

• Aug 16, 2023

• #13

If it was the rocker covers, wouldn't I see much more oil on top of engine around the covers? I tend to think it's the valley gasket more so.

I think I will try to replace both rockers and valley gasket while I am at it....

 

kermit_rr

Very

Full Member

• Aug 16, 2023

• #14

jrod2550 said:

If it was the rocker covers, wouldn't I see much more oil on top of engine around the covers? I tend to think it's the valley gasket more so.

I think I will try to replace both rockers and valley gasket while I am at it....

Click to expand...

depends, if the rocker cover is leaking only on one corner, it could be deceiving

 

Mark Piercy

Well fumbled member....

Full Member

• Aug 17, 2023

• #15

Also the fan is constantly blowing everything rearwards, even oil flow from gaskets. Wash it down, idle it for a while and with a mirror and torch check around engine in that area .