Source of oil spray?

[apsilon]

1 day into being registered and first problem.

 

Decided I'd take the 240Z out for a little run this morning just to check for any problems as she hasn't been driving other than to or from the workshop. So headed out, all well, then after cruising along in 5th at an indicated 80km/h for about 15min the engine dies. First sign of trouble. Restarted while still rolling with no trouble and all gauges are reading normal. I immediately turn around and head for home just in case and I'm glad I did.

 

There's clearly been an oil spray under the bonnet but I can't see a source. There's oil over a lot of the passenger side inside fender and underneath the bonnet itself. Few other spots but clearly where it's dripped down from being on the bonnet.

 

Weird thing is (maybe not, don't know much about aerodynamics) is that there's oil starting from the very front left corner of the bonnet all the way back to the firewall. Even some on the outside.

 

Whereever it's come from it must be in front of the engine or at least pointing forward as it's only hit the bonnet at that point, ie nothing over the engine itself.

 

I've only driven her 3 times before this and there's been no issues so I'm thinking it's related to the sustained cruining speed. I'm waiting for her to cool down and I'll check for oil in the rad but I'd appreciate any suggestions of where and what to look for as engines really aren't my thing past maintenance and theory on how it all works.

 

Thanks.

[gav240z]

Very strange indeed, I've certainly not heard of this problem.

The oil breather pipe in the top of the valve cover, how is that? Is it blocked off? Has it been fitted with a K&N style filter?

 

If you block off the oil breather pipe it will cause the engine to build up lots of pressure. Usually this is re-routed into the air filter box but if your carbs have been changed I suppose this could have been blocked off.

 

Is the dipstick in position?

 

I honestly can't think of anything else at this stage. Perhaps a picture of your engine bay will help?

 

[apsilon]

I've just been out having another look and can't ID the source. For it to be up under the bonnet etc it has to be a leak up high right and not down around the block right?

 

Breather isn't blocked off, it feeds to the stock air cleaner and disptick is in place (but that's the other side of the engine bay anyway). No oil in rad BUT oil level has dropped a lot (no surprise really) but what's left appears very watery in appearence (water level in rad hasn't dropped). 

 

All fluids and filters were replaced this past week so any contamination is a symptom of the problem.

 

At this stage my next step unless someone has other ideas is to top up the oil and start the engine as it's clearly only coming out under pressure (there's drip trays under it and they're dry). Issue there is I don't think it's a problem that will appear quickly. I'll check if the radiator bubbles while it's running (sign of a head/gasket issue right?).

 

I grabbed some pics earlier so Ill resize those and get them up as well.

[apsilon]

OK, pics are up. I won't insert them here as I've left them largish so things can be made out so I'll provide links instead.

 

Left side of the engine. Fairly stock AFAIK.

 

Right side of the engine. You can see the left hand front corner and how dirty it is from the oil.

 

Under the bonnet. You can see how the oil is at the front and left side.

 

Left side guard. It used to be fairly clean.

 

Another angle of the mess at the front left.

 

Left side of the firewall. You cans ee the oil has even made it back here.

 

Outside front left corner of the bonnet. I'd started to clean it up already here but you get the picture. How does oil end up here?

 

This pic I will insert. Should either of these barbs go anywhere? They're the only ones that don't have hose on them but as they're to do with the carbs I don't think they could be related to this issue. BTW Can anyone ID the type of carb?

 

 

 

 

 

 

 

[apsilon]

OK, so I put a couple of litres of oil in and started her up. No sign of oil leaking or spraying anywhere that I could find but didn't want to run her for too long without knowing what's going on. Also no bubbles in the rad.

 

I did find a fairly significant fuel leak however  and fixed that so at least that's something.

 

Hmmm. just thought of something. This fuel leak was right at the front of the engine, just after what I assume is the regulator so it was squirting onto the front of the engine and down on to the belt etc. Is it possible that what I'm seeing is actually fuel that's collected dirt/grease/oil from the front of the engine then been thrown around the engine bay by the belt/fan? It is really sticky as opposed to just slimy.

 

The fuel leak might also explain the engine dieing suddenly if pressure dropped enough right?

[Zedman240®]

With the stain on the outside of the bonnet, the oil/fuel wouldve been running or squirting to that side of the bonnet underneath and the wind while you were driving started to blow it back towards the windscreen. As for the two hose connections, the small one on the float chamber is the fuel overflow; which should have a hose going to the air cleaner. The other one I'm not sure of. These carbs look like they are from a Jag or just the S.U type. I would check all hoses, gaskets and check all bolts for tightness.. Without seeing it in person its a bit tricky..

[apsilon]

Without seeing it in person its a bit tricky..

 

Yeah I know.

 

Everything looks OK but I'll check all bolts etc. I'll also run some hose from that barb on the float chamber to the air cleaner. There's a port on the cleaner which isn't connected so this must be where it's supposed to connect to.

 

Going to speak to a few people through the week and if anyone has any further suggestions I'd appreciate it. At this stage my plan is to next weekend, drop the oil and refill with fresh so that I know it's at the right level and also check if there is any contamination as I still think it's consistency is too watery. Complete degrease to help spot any leaks then do laps of the neighbourhood to get it up to temp and basically see what happens. I'm thinking that maybe something warps once it's at full temp and then starts to leak hence it not leaking with it just running for a minute while cold.

 

The fuel leak was significant and most of it would've ended up down on the pulleys and with the direction they rotate would've been thrown up and to the left so I'm hoping that's "all" it is. Does fuel pressure rise with revs on carb engines or is it static? if it does increase, given the maount that it was leaking at idle it would've been a fountain at driving speed. I'm probably a bit lucky.

 

Thanks for the suggestions so far.

[Glen]

Is it possible that what I'm seeing is actually fuel that's collected dirt/grease/oil from the front of the engine then been thrown around the engine bay by the belt/fan? It is really sticky as opposed to just slimy.

 

The fuel leak might also explain the engine dieing suddenly if pressure dropped enough right?

 

Im no mechanic but here's an idea. You can normally tell if it is oil straight from the motor or not just by looking and when you got home it should still have been quite runny and very hot, Your fuel leak theory could be right looking at the splatter pattern on the under side of your hood. Get your finger and wipe some off and have a wiff. if its fuel it will still be fairly strong. You should be able to tell the difference between oil and fuel. Also looking at the car from front on the fan belt runs counter-clockwise which also follows the splatter pattern

[Glen]

The fuel leak was significant and most of it would've ended up down on the pulleys and with the direction they rotate would've been thrown up and to the left so I'm hoping that's "all" it is. Does fuel pressure rise with revs on carb engines or is it static? if it does increase, given the maount that it was leaking at idle it would've been a fountain at driving speed. I'm probably a bit lucky.

 

Looking at your pictures yours is a mechanical fuel pump, which i think (dont hold me to it) works harder as the rpm's rise. So yes the fuel pressure would be stronger as the revs rise.

[apsilon]

Well the whole car smells a bit like fuel ATM so it's hard to tell. It's certainly not like what oil looks/feels like out of the sump. I initially thought oil because what's been thrown around is black but as I said earlier it's sticky and was right from the start, but fuel evaporates and it could be just leaving behind what it's collected. The only thing worrying me here is that there's no residue on the fan or belt. That could be because my theory is wrong or it could be because the fuel was thrown off and the rest had evaporated by the time I thought of it.

 

My other concern is that the disptick shows a thin light grey oil, not brown or gold or black like I'd expect. It looks like water contamination to me but I'm no expert. I should be able to tell for sure once I dump it.

[Glen]

hmmmm water in the oil, not good. Hope you have a mechanic that you really trust or maybe some Z members in your area that might be kind enough to help you out.

[pauly_adams]

water in the dipstick isnt always a sign of water in your oil. have you washed your car whith a presure washer before ? if so like me and my dipstick you may have got a small amount  of water in there, also with the oil i use 10w30 or 15w30 and trust me its thin works realy well until you get a small leak it does what you said happerned to your car it sprays all over the place. i had a small oil leak at the rear of my rocket cover and it sprayed oil, under moderate exceleration all over my firewall, and all down my gearbox till it final stoped half way down my tailshaft. also my engine breather had a hose going to my airfilter and i thort it may have caused a vacume and when the hole formed the oil escaped. just a thort and good luck

 

cheers pauly

[pauly_adams]

i also forgot to mention something your z and a mini have one thing in common the carbies, they are off a mini or mg as my mothers mini has one and its the original carb it should be about 1.5 inch if so its them

 

cheers pauly

[apsilon]

have you washed your car whith a presure washer before ?

 

I haven't but my mate may have as signs of an oil leak aren't something you want during blue slip inspection. There was a leak around the oil pressure switch which is near the dipstick so he may have hit the area to clean it up after it was fixed. I'll have to check. If it's not that shouldn't the water level in the rad drop or show signs of oil?

 

Mini carbs hey? Stupid question probably but 1.5" where? I'm more of a EFI guy. Runs OK IMO but the only other Zeds I've been in were either modified or in pretty bad shape (those that ran at all) when I was shopping around for mine so maybe it should be better.

[Zedman240®]

Pauly means 1.5" in the carby's throat diameter. Remove the air filter cover and look into the throat and measure the opening. As long as your oil doesnt look like a "cafe latte" it should be fine. If oil is a coffee color you may have a head gasket "issue". Usually there never is oil on the belts or fan because they are spinning at how many rpms and nothing can really stick to it while its running. Like you said before, it could be fuel from the leak, collecting oil from the block, flying off sticking to the underside of the bonnet, fuel evaporates leaving the oil stains. Hope you find the problem!

[nat0_240_chevZ]

OK, IVE HAD THIS ON A FEW ENGINES, NOT  ALL L SERIES, IT LOOKS AND SOUNDs LIKE A High (sorry bout caps) high pressure oil leak from the timing cover, could be either gasket or a crack in the alloy cover itself over on the passenger side.

now YES your oil pump is on the drivers side but im almost certain one oil port goes over the pass side, now this is/was where my g/f's gemmi was leaking as was an ol L4 of mine (datto 200B, ie L20).

 

Track down the source by degreasing and spinkling baby powder around the timing cover and oil pump (as it also could be spraying from there). yes baby powder the lot so it looks like casper (or use cooking flour??? up to you.)

 

And as for highway driving, this increases you oil pressure to its near max, as oil pressure (if your pump is good and oil too) doesent get much greater after 2000 rpm just flow increases, so prolonged highish rpms makes the oil piss out in a very fine spray, and gets blown by the engine fan all over the engine bay. whatta mess.

 

all i can say if its the timing cover replace, if its just gaskets also replace.

its not an easy job and yes can be done without removing the head, see workshop manual, but can be very tedious. after doing mine the spray was gone and was able to keep a clean engine bay!!!

 

hope this helps, please feel free to ask any Q's

 

no problems, nato

[apsilon]

Thanks Zedman240, I'll check the carb size on the weekend but as it runs OK and I'll be swapping the engine long term I don't think I'll bother changing them at this stage. So what's the normal size for an L26?

 

nat0_240_chevZ, I'll chek that out, thanks. I'm going to degrease the whole thing this weekend anyway. Thanks for the tip about the baby powder. Nice idea 

[apsilon]

Don't know why I didn't think of this myself. Speaing to a mate this morning and he believes the reason it's sticky and black is the fuel has stripped some of the under bonnet sprayed on insulator away. You can see where it's white in one of the pics. It had a missing patch before so I can't say how much it's changed but the theory is this stuff is old and likely to be bituman based. Fuel sprays onto it and softens/strips it. It then gets blown around and drips down etc looking like oil. Also explains why it's sticky.

 

I'm feeling better about this not being such a major issue.

[nat0_240_chevZ]

how do you explain the low oil level, to her up and see how you go, you mates suggestion IS plausable however, and likely.

 

but doesnt explain the low oil level,

 

keep us all posted

 

nato

[apsilon]

No it doesn't. I have a theory but won't be able to prove it. Regardless I'm going to change the oil and monitor it. Hopefully it's all OK.

[apsilon]

OK, so today I dropped the oil. It doesn't appear to have water in it but it did have a little something in it so the flush won't hurt. The oil was from the workshop and was something I hadn't used before. Can't recall the brand now, starts with an H? Don't like it's appearence or consistency so won't use that again.

 

Also cleaned up the mess and then took her for a run out to Windsor and back. No problem at all. No signs of any leaks, drips or sprays and fuel economy is much improved LOL.

 

Hopefully that's it. I'll take her for another run tomorrow if I get a chance, if not I might driver her to work through the week. The stop start traffic would be a good test for the cooling system etc anyway.

 

EDIT: Oh and thanks to all for your ideas and suggestions.