Oil Blowing Over Engine Bay

[Bigtimmy 1]

Well I did my first track day with me new engine setup.

 

1.9 8v, Piper cam, lightened and balanced bottom end and a set of twin 40's.

 

I had it rolling roaded on Friday and was pleased with the result.

 

I did a couple of sighting laps first off then came in and checked the fluids, and there were a few spots of oil under the car, which was no drama, I know I've got a sump spacer issue.

 

Checked the water, all fine, decided to top up the oil and found some mayo under the filler cap, and crapped my pants thinking hgf!

 

After topping the oil up I went ouot and did a few laps, nothing too hairy, just a nice steady pace.

 

It ran up to temperature fine and sat there, just over half, oil pressure was fine, it went up, then tailed off a bit once the oil warmed up.

 

Went back in and opened the bonnet and found an interesting "splatter" of oil over the bulkhead below the coolant tank.

 

It looks like it has come out from the head gasket on the back corner, then dribbled down the back of the engine and dripped off the diff casing.

 

Checked the oil, all ok, checked the water once it had colled a bit and it was fine, smelled like water with antifreeze, then checked the filler cap and hey presto no mayo, but a few tiny spots of water.

 

I can only assume it was some moisture in the system causing the mayo, possibly from the catch tank which is metal and would cause some condensation.

 

I ran another 4 or 5 sessions through the day pushing the car more and more (and myself at times) and the gauges and subsequent checks were all fine, but the drippy oil remained.

 

Could my oil drip be coming from somewhere else other than the hg and what should I do with it, if anything?

 

Your thoughts would be greatly appreciated.

[thug pug 7 1 Cars]

Has your dip stick got a good seal on the dip stick tube as this is where most 205's push oil out if the seal is not great.

 

Rab E.

[unariciflocos 49 1 Cars]

My first guess would be rocker cover gasket, second... distributor seal?

[steve@cornwall 100]

Has your dip stick got a good seal on the dip stick tube as this is where most 205's push oil out if the seal is not great.

 

Rab E.

 

Can easily blow oil from the dipstick tube at high revs if your breathers aren't A1

[Bigtimmy 1]

I spent a bit of time looking for the leak during my trackday, as I didn't want to cause any damage.

 

It isn't the dipstick, I ran my finger down the tube and there was no oil. This was a problem I had with the old engine and was easily solved with some electrical tape. The seal on this dipstick is 100% better than the previous one so I doubt it's that.

 

It isn't the rocker cover gasket, it was new when I rebuilt the engine and the leak is further down than that.

 

It could be coming from the dizzy, I couldn't see below it, I'll take a look in the morning.

[M_R_205 5 1 Cars]

I had quite an impressive leak when i forgot the allen key bolt behind the Dizzy, that holds the casting to the head? Another possibility as it sprayed oil in tthe same place as you have mentioned....

[Bigtimmy 1]

Well here we are on Thursday and I've finally got round to looking at the car to see if I can spy the oil leak.

 

With the aid of my trusty phone camera and photoshop I can show you the route of the oil and I guess the source, which must be the hg.

 

Everything above the line of the gasket is dry and clean of oil.

 

 

Sorry about the unhappy man

 

So I then decided to check the oil and water again, and still no change, no oil in the water and no water in the oil.

 

So I took the filler tower off and found more mayo than a Hellmans factory in the filler pipe, as shown in the photo below.

 

 

Again with the unhappy man

 

I then decided to do a compression test which came back as follow.

 

From the water pump side to dizzy side.

 

1 - 10 bar

 

2 - 9 bar

 

3 - 9 bar

 

4 - 8 bar

 

I've always considered having a nine bar to be a good thing, however I can't work out whats going on here. It does seem like it is all pointing to HGF which is upsetting.

 

Any suggestions before I start taking the whole lot to bits again?

[pug_ham 244 3 Cars]

It could be oil leaking from underneath the dizzy housing between where it bolts to the head but before starting to strip it down again condeming it as HGF get a sniff check done at a decent garage.

 

Graham.

[Anthony 1,003]

I wouldn't immediately condemn the headgasket - it's cold and the breather systems love to gunge themselves up with mayo.

 

Most HG failures I've seen on XU5/XU9 engines never go between oil and waterways anyway, so you rarely get oil and water mixing. It's normally cylinder to waterway, leading to a pressurised cooling system and coolant loss, and eventually poor running and white smoke when it gets bad enough

 

Also worth remembering that with a big cam your compression figures will be down a bit on what you'd expect from a good standard engine (12+ bar on an accurate tester).

 

I'd personally start by clearing out the mayo gunge out from the breathers and seeing if it still leaks - if there's enough in there, it won't be able to breathe properly and will end up forcing excess crankcase pressure through whatever the weakest point is.

 

Given the location of the leak, I'd be more suspicious of the thermostat housing seal personally anyway given that the top half of it is oil rather than coolant - the pressurised side of the oil system is at the other end of the engine, and I wouldn't expect the unpressurised return to leak sufficiently to spray over the bulkhead without the adjacent waterway leaking as well.

[Bigtimmy 1]

Thanks for the replies, I decided that I needed to check the whole thing out properly.

 

So at 1430 this afternoon I started to take the engine out and by 1700 it was out and the head was off.

 

There isn't any real sign of hgf which is a bit of a bugger. I took it up to my Jedi at the garage and we looked over over it and couldn't see anything amiss with it.

 

I'll check the various housings over tomorrow and see if anything is wrong there, but I'm a bit stumped to be honest as the head itself was clean and oil free when I checked it over.

 

Still on the plus side I can get the engine out of the car and onto the bench and head off in two and a half hours which is good to know!!

[Bigtimmy 1]

Ok so I've got a bit further.

 

As I mentioned it doesn't seem to be hg related, but the oil must be coming from somewhere!!

 

I have the head on the bench and I've carefully taken off the thermostat and dizzy block and it all looks as it should.

 

I have had a good look at the block, and there's nothing out of the ordinary there either other than a bit of the block "missing" shown in the photo below, but that's a waterway not oil.

 

 

"Missing" bit of block

 

I also took a photo of the block side of the gasket in the same area and other than the two arrowed bits it was all good, and agin a waterway rather than an oil gallery.

 

 

So really nothing out of the ordinary.

 

What's my next move, do I send the head away and have it crack tested to make sure its ok, is there some sort of test I can do on the block to make sure thats as it shoud be??

 

Although it's a pita, I'm quite enjoying this whole search and solve mission!!

[PhilNW 44]

Had a similar problem after swapping a blown head gasket,

 

Any oil at the top of the engine should be gravitating back to the sump. The oil is splashing around but is not under pressure so is probably making its way past a gasket and dribbling down the engine where it is blown onto the bulkhead when on the move but not when stood still.

 

"It looks like it has come out from the head gasket on the back corner, then dribbled down the back of the engine and dripped off the diff casing."

 

Sounds exactly like mine

 

Took me ages (and I mean ages) to find the true cause/source of the leak but in my case turned out to be the rocker gasket where it curves over the distributor drive and dribbling down the engine, bit of sealant under the gasket cured it

 

Phil

Edited February 26, 2011 by PhilNW