306 S16 with mayo in the oil

Alby

Alby

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Carrum, Vic
Hi everyone,

Just bought my third Peugeot after previously owning a 205 Gti & a 306 Gti6. This one is a 306 S16 with a few problems.

Main problem is mayo in the oil, a fair bit of it. No oil in the water, just the other way around. Engine runs very well, no overheating but does lose a small amount of water, presumably getting into the oil.

I guess this is a head gasket job, but thought I'd check first if there might be other causes of this on these particular cars.

Any thoughts would be appreciated. Also looking for a good Peugeot mechanic in the Frankston, Victoria area who would like to fix this for me.

Cheers, Alby
 
Is the oil a milkshake, or not? They have very few issues, if well maintained and should see 400,000K untouched. You won't know until the head is off. At the same time, change water pump, cam belt and service the hydraulic lifters. I can do these for you, if you're not competent. Don't be tempted by aftermarket lifters. Also start shopping for all the breather & oil hoses. They will crack in your hand on removal.

If the head is too corroded, I have an excellent 2nd hand one I'd be prepared to part with.
 
Hey Peter,
Thank you mate. I've been reading up on all your posts about these cars and once I've got this issue sorted & the car registered I was planning to contact you about a few simple performance improvements. Will still do that, but probably after Xmas at the currant rate of progress!
I'm in Carrum Vic and had the impression you're somewhere in NSW which would make getting the car or engine to you cost prohibitive at this stage. I would be competent to do the basics of lifting the head, new head gasket, etc but at the moment have neither the time nor a place to do the work. Hence my request for suggestions of good people in this area.
To tell you the truth, the engine runs so well I find it hard to believe that there is anything wrong other than a gasket break letting water into an oil gallery. However, I know it could be something more serious. Car has done 204k kilometers & seems to have been serviced reasonably regularly, so engine should still be good.
Are you in NSW or somewhere nearer?
 
Another thing to check before you commit. A potential failure point is the oil to coolant intercooler. I would remove it all and replace with just a new oil filter (and oil change) before doing anything else. The XU10J4 block doesn't have a male barb however, so you'll need to find an M20 barb from an alloy XU9 or similar.
 

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Thanks Peter, great suggestion. Would be nice if it turns out to be it! Will let you know
 
PeterT said:
Another thing to check before you commit. A potential failure point is the oil to coolant intercooler. I would remove it all and replace with just a new oil filter (and oil change) before doing anything else. The XU10J4 block doesn't have a male barb however, so you'll need to find an M20 barb from an alloy XU9 or similar.
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Hi Peter, I've occasionally wondered which fluid is at the higher pressure in this litte intercooler if it's faulty, at idle with lowest oil pressure I think the radiator cap has a higher psi allowing water to be forced into the oil, but at higher revs I thought the oil pressure would be higher and forcing oil into the water? Or have I got it all wrong?
 
I think you're probably right Alex. I'm just trying to think of all the possibilities where oil and water can meet. Thus why I asked if the oil was a milkshake. This would indicate coolant had leaked into the oil, whilst not under pressure.
 
Very interesting analysis guys.

There's been a possible new development here & I'll be as specific as I can as per the following steps:

1. Car was advertised with signs of water in the oil.
2. When I first saw it I lifted the oil cap & sure enough there was that milky brown milkshake look inside the cap. Couldn't find any sign of oil in the water. It became obvious that the car had been unregistered for over 2 years & possible unused except for a couple of short drives for a bit longer than that. At that stage I walked away.
3. A few weeks of looking at other cars later, I decided this one might be worth a bet, so went back, negotiated a price & bought it. Drove it gently home on a temporary permit - 1.5 hour drive. Car ran very well, I was pleasantly surprised.
4. As soon as I got home, checked the cap again. Lots more off that brown milkshake look all around the cap. Also noticed something I hadn't noticed earlier (may not have looked hard enough). In the remote filler there is a catch tray with holes in it about 40 or 50mm below the top. Under that the filler bottom & sides were caked with more of the sludgy brown milkshake look. Also some milkshake sludge on bottom of dip stick.
5. This led to my first post saying there was a lot of mayo in the oil.
6. A day later I drained the oil, looked hard at the drained oil, but found no visible signs of water. Refilled with fresh oil, cleaned the cap & top part of filler but couldn't get through holed plate to clean bottom part of filler. In any case the stuff below the catch plate seemed to be very dried on, not easy to wipe off.
7. Went for a longish drive & then checked filter and dipstick again. Some new brown sludge but nowhere near as much as earlier.
8. Yesterday I cleaned it again and went for another drive. This time no new sludge in either oil cap or dipstick! Will go for another longer drive today & see if that still holds.

Could the issue simply be water condensation inside the engine from being parked outside & not being driven for 2 or 3 years?
 
Sounds like it - good on you for not panicking and just taking it step by step!
I used to get a bit of the same issue with an L series Subaru - I think the flat 4 design might have contributed.
 
Thanks Peter. You’ve encouraged me to start focussing on a few rego issues but keep a close eye on the oil in the meantime.
Hopefully I can get rego fairly quickly & then think about some basic improvements.
Thanks mate, cheers!
 
PeterT said:
I think you're probably right Alex. I'm just trying to think of all the possibilities where oil and water can meet. Thus why I asked if the oil was a milkshake. This would indicate coolant had leaked into the oil, whilst not under pressure.
Click to expand...

Thanks Peter, if I was to continue this train of thought then the most likely scenario for this little cooler to have water leak into the oil is on a very hot day with over 104 degC water temp and water pressure close to (I'm guessing) approx 17 psi radiator cap rating and then turning engine off so there's no oil pressure pushing back on the water jacket.


Alby said:
Thanks Peter. You’ve encouraged me to start focussing on a few rego issues but keep a close eye on the oil in the meantime.
Hopefully I can get rego fairly quickly & then think about some basic improvements.
Thanks mate, cheers!
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Alby, it's possible the remote filler and breather hoses are more prone to trapping condensation as I recall some slight mayo on an S16 I had.
My suggestion to help confirm if there was or is a problem is to make a U shape pipe to join hose 1 and hose 3 and thus bypass the little cooler while you focus on fixing other items for RWC. Probably should also seal the open pipes on the cooler to stop any dirt getting into the chamber.
At a later date if there's no sign of mayo and you've sourced a new seal (1104 24) then remove the cooler from block and carefully inspect if there's any oil in the water jacket side, refit some water hoses and use a radiator pressure tester up to the psi rating of the radiator cap and see if there's any loss of pressure or water coming through to the oil jacket side.

Or if U pipe is too hard to fit then leave water pipes fitted and remove cooler and refit oil filter direct to block and leave the chamber floating above the filter.

cheers
AlexB


All the part numbers in pic below are in these shortened links to the 306 S16 online parts catalogue


1698282170249.png
 
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Alby said:
Could the issue simply be water condensation inside the engine from being parked outside & not being driven for 2 or 3 years?
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Yes, definitely. Condensation in the cap is common. If the oil is oil, and not a milkshake, you have less to worry about. I'd still test for CO in the coolant and get it pressure tested, before anything else.
 
Thanks Peter & Alex, lots of great suggestions which I will certainly follow. Did my longer run today & still no new water in oil signs.

In fact I was comfortable enough to spend a few happy hours finding out what other challenging issues this car might have by trying to find out why the heating/ventilation fan doesn't work. Boy, there are a few possible reasons for this. Finally found the issue as the multi pin female plug in the back of the fan speed control, had a small burn mark in one corner. As soon as I switched on the ignition without this being plugged in, the 30 amp fused survived whereas previously it was instantly burning up. Next step is finding out whether heater control modules are easily available here. Probably not, haha.
 
Alby said:
In fact I was comfortable enough to spend a few happy hours finding out what other challenging issues this car might have by trying to find out why the heating/ventilation fan doesn't work. Boy, there are a few possible reasons for this. Finally found the issue as the multi pin female plug in the back of the fan speed control, had a small burn mark in one corner. As soon as I switched on the ignition without this being plugged in, the 30 amp fused survived whereas previously it was instantly burning up. Next step is finding out whether heater control modules are easily available here. Probably not, haha.
Click to expand...
High probability it'll just be worn out brushes in the fan motor, very common thread on Aussiefrogs. Get upside down in passenger footwell, unplug the chunky three wire plug and 4 torx screws to drop it out.
Scrape out the worn metal filings from the gaps between the armature segments and retest.

Blower Motor Bearing/Bush lubrication

Blower Motor in a Peugeot 306 had siezed so I figured I'll fit new bearings. Pulled the armature apart and found it has sprung mounted bushes and not replaceable ball bearings. Once I cleaned away all the dirt I can see a felt pad inside the housing so I figure it's unlikely to be there for...
www.aussiefrogs.com
 
AlexB said:
High probability it'll just be worn out brushes in the fan motor, very common thread on Aussiefrogs. Get upside down in passenger footwell, unplug the chunky three wire plug and 4 torx screws to drop it out.
Scrape out the worn metal filings from the gaps between the armature segments and retest.

Blower Motor Bearing/Bush lubrication

Blower Motor in a Peugeot 306 had siezed so I figured I'll fit new bearings. Pulled the armature apart and found it has sprung mounted bushes and not replaceable ball bearings. Once I cleaned away all the dirt I can see a felt pad inside the housing so I figure it's unlikely to be there for...
www.aussiefrogs.com
Click to expand...
Thanks Alex, will give it a go!
 
Oh, and be really, really gentle removing the drain hose if it's not already broken off from bottom of fan.
A blocked drain pipe and brushes sitting in water is the other cause of fan failure.
 
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