Help finding a leak

siege · Postby **siege** » Thu Mar 08, 2018 9:35 am

So I've got a slow leak dripping from somewhere, I cleaned the plastic underbody tray a month ago and it's filthy again, with drips on the road. So I want to find and fix it. I've done a bit of reading about the usual culprits but would appreciate any insights thanks

Engine oil is at full line (0W-40 when I changed it i put in about 200mL too much by mistake, leak preceded the oil change )
Power steering reservoir 75% full, today is the first time I've checked this
Coolant is full
Brake and clutch master cylinders are full

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You can see that the sump is covered in a film of ?oil

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The rear of the engine doesnt have any oil around the valve cover or cam angle sensor though

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I can't see any leak high on the front either

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And this is looking at the front from the exhaust side close up. No messy oil here

siege · Postby **siege** » Thu Mar 08, 2018 9:43 am

The heaviest grime seems to be concentrated at the front left side of the engine. This is where most of the spill on the plastic underbody tray is.
There is also a heavy amount of grime to the left of the crank pulley on the outside of the oil pump and even more on the A/C compressor.

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Here you can see the dirty AC compressor body

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This is a closer shot in between the AC compressor and power steering pump. There is some crap on the bottom of the pump too. The engine block looks clean

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This shot is looking down on the power steering pump and AC compressor from the exhaust side of the engine bay close up

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For completion sake, the alternator is clean. Also, running my finger around the oil filter I recent replaced, there is no oil leaking around that

So I guess I'm biased. I really don't want this to be an oil pump or sump that needs to come out as that would be very expensive. My feeling is that it's actually a leaking power steering pump spilling power steering fluid rather than oil. Does anyone have any other thoughts? Other places I should be looking? remedies to start off with? Thanks in advance

ralt · Postby **ralt** » Thu Mar 08, 2018 10:35 am

Hi.
I may be typing the obvious but if it was mine I would degrease the bottom of the engine let it dry thoroughly then start the engine and check for leaks. Fairly simple task.

93_Clubman · Postby **93_Clubman** » Thu Mar 08, 2018 10:40 am

IIRC, you bought the car very late last year. Since buying it have you cleaned the engine? If not, then these are inherited leaks/spills, & who knows what a PO has done.
The one on the cold side (driver side in RHD) looks like what occurs following a number of oil filter changes which aren't cleaned up at the time. Hot side leak/spill might be from something else.

siege · Postby **siege** » Thu Mar 08, 2018 11:12 am

Good points. A lot of this may have been there for a long while
It's definitely still dripping on the ground and undertray though.

I'll hit it with a quick degrease now

93_Clubman · Postby **93_Clubman** » Thu Mar 08, 2018 11:23 am

siege wrote:It's definitely still dripping on the ground and undertray though.

Ok, so which side of the engine, & front or back, are the drips on the ground under?

siege · Postby **siege** » Thu Mar 08, 2018 12:00 pm

The drips are slightly to the left of the midline on the road when parked. The left side of the undertray was dirtier than the right when I cleaned it over christmas after buying it.
The back of the engine is clean
I've just degreased the whole bay with an aerosol can and hose. The left side was dirtier.
I figure if I drive it around and then have another look on the weekend I might find a fresh leak?

siege · Postby **siege** » Wed Mar 21, 2018 7:43 am

Had the car up on a hoist and looks like the freshest oil is actually at the rear of the sump. Mechanic thinks rear main seal.

It's very slow and I've only noticed it since changing to 0W-40 oil so maybe I'll put 5W-40 or 10W-40 in and see if it stops. Not keen on doing the rear main until the clutch goes.

RS2000 · Postby **RS2000** » Wed Mar 21, 2018 8:48 am

siege wrote:It's very slow and I've only noticed it since changing to 0W-40 oil so maybe I'll put 5W-40 or 10W-40

I can't see that making any difference as they're all 40 weight oils, so will be close to the same viscosity at operating temp.
Also, the difference when cold at ambient temp will be very small, unless you're in below zero conditions.

hks_kansei · Postby **hks_kansei** » Wed Mar 21, 2018 3:58 pm

Keep in mind it could also be the front seal on the gearbox too.

If it's the rear main just make sure to keep the small drainage hole clean (on bellhousing) and chekc oil often.

get it fixed when you can, but as long as you can put oil in the top faster than it comes out the bottom it's nothing major, just annoying.