Hi,
89 240,B230F N/A, 330K km on the engine, stock everything except a T cam been dropped in 1 month ago. Car has a funny oil leak from the connection between head and block, on the oil filter side. Other side totally dry. Leaking is not too crazy, just enough to cover the block and creating little mess, a few drops on the floor every night. Has been doing this since I bought it and I guess its been doing so for a long time cos the engine bay was really dirty when I got her.
Never need to add oil between oil changes, coolant level never drops or over pressured, checked old oil, looks normal, exhaust looks normal, water condensation from exhaust looks like normal water. Currently added in 8/10 bottle of lucas leak stop during oil change all time, didn't feel any different, might leaking less, but couldn't tell, car has some typical valve tapping noise all time and some piston slap (small sound ) noise during cold start. Nothing unusual.
Did an oil cap test, it can suck down the oil cap, not strongly but oil cap stops dancing. When rev, a stream of smoke will come out of the dipstick, then disappear in 2 secs. But I can never check this when going on highways or pushing hard up a hill (Lots of hill where I live, that's why I decided to get a T cam)
The thing makes me concern is, if the system is somewhat still pressurized, I assume it will blow my seals faster, and replace some of them is a big pain. Also I don't like oil on my rubber parts especially water pump area. So I'm just curious if anyone had similar issue to this or anyone likely to know where the problem is, or I can just live with that ?

Thanks in advance.

Work done:
PCV system cleaned (took everything off and cleaned), vacuum works good, new hose
New cam seal, crank seal and rear seal
Throttle body cleaned, wasn't too bad
New valve cover gasket and seal
New thermostat, upper radiator hose, checked coolant when replacing, all good
Did a dry compression test, almost 180 psi all around, some higher some lower, but very small difference, checked spark plugs by that time, looking nice and good
Idle sometimes getting little bit funny especially in cold environment, have a tacho, looks like car is trying to bring up idle speed, but eventually settle at slightly above 800rpm, never a issue, warm days wont do this
IAC, MAF cleaned


Upper of the engine stays clean once I cleaned everything up.

 

clean it up with foaming engine cleaner ('gunk', etc), let it dry, add a vial of fluorescent oil dye, drive it a short distance, inspect in a dark place with a UV flashlight, if you don't see where the seepage is, drive a little longer, repeat til you do.

any leak between the head and block is a head gasket issue. my 1992 740 T wagon was seeping oil there on the exhaust side around cyl #3-4 for a couple years before it finally blew the gasket

 

I have the same issue on my 89 740 with 380K miles on it. Doesn't use oil just leaks it a little. Being an old Jaguar guy I'm used to the oil leaks . In Jaguar land this is called "controlled seepage" so I'll let it go until the head gasket decides to give up.

 

Thanks. I actually had the dye in previous oil change, it was from head gasket area, a little from the cam plug. I guess I just keep an eye on everything and let it go then. What's creating that much pressure tho, I feel there's nothing really pressurized on that side.

 

Thanks, how long you been going with the leak? Did it go worse or kinda stays the same?

 

with it idling, loosen the oil cap (using a thick rag!!)... does the loose oil cap blow off or just rattle around ?

if the loose oil cap blows off then you probably have a clogged oil trap, which is the red block's PCV system.

 

Thanks for the advice.

The cap kinda just jumping little bit, not really fly off. It can stay on there, when I rev it will jump first then suck down, I feel this reflects the smoke from the dipstick. Oil trap was also taken off when I replaced the hoses, basically entire PCV system was off, cleaned, new hose all around and reinstalled. I feel there should be enough vacuum when engine is empty loaded, just not sure when I push it up hills will the blow by exceed the vacuum capability.

 

We had an 240 '89 wagon for 15 years. In the last 5 years of that it developed a leak in the same place. I just left it as it was small and put a pan under it in the garage. Never did blow the gasket. Just keep the flame trap clean to keep the internal pressure low and you should be ok.

 

Can't remember but it's been a while. I'm talking years so gauge it from that. It takes about a quart over 5000 miles but way back when I had the oil trap plug and got a leak in the rear seal. I still haven't changed that so it still weeps oil. Car still runs great and I only use it locally which is about a 50 mile radius. It was my wife's baby and after her recent passing I'm trying to hit 400 K miles . If I make it I'll assess if I want to continue to try for more miles or sell it. If it blows I may sell it or get it crushed. We'll see. I just ordered a new C8 Corvette convertible so the Volvo days will be limited when I get it.

 

Thanks, I guess I will leave it that way and enjoy some free anti-rust coating then

 

I see, I feel it's kinda normal to lose some fluid every 5000 miles on these old engines, my car does it all time but by then its time for oil change, sometimes this car travels little bit and I really have to push it through mountain highways which is my main concern, I guess as long I have the flame trap clear it wont got enough pressure to really blow anything then. Thanks for the info and enjoy the C8