So my car is a 1990 740 gl non turbo. There appears to be quite a lot of oil in the engine bay despite cleaning it out last night. It looks like someone before me replaced the valve cover gasket and did not do a very good job. sealant can be seen on the outside of the valve cover and it just looks weird, so I will be replacing that regardless. So the valve cover is definitely leaking at least a little bit of oil, but it looks like along the head gasket quite a bit of oil can be seen as well and it really looks like it is leaking. the oil filter always seems to have a lot on it which is clearly dripping from above. The top of the valve cover gasket is cover in oil too. Car runs great though no issues with overheating or anything else. Sorry this such a choppy post just wondering if it is possible for it to be a head gasket leakage and run great, or if it is likely an illusion of the valve cover gasket just leaking all over everything. Thanks in advance

 

another common source of oil leaks are the shaft seals, especially the camshaft seal. oil from this leak blows back and coats the whole engine.

there really shouldn't be any sealant on the valve cover gasket, btw, except little dabs of permatex at the corners of the camshaft seal covers where the gasket has to make sharp bends and won't seal well. use a real Volvo gasket, the aftermarket ones mostly suck.

get yourself a ultraviolet LED flashlight, they are pretty cheap now. go to a car parts place, and ask for some ultraviolet oil tracer dye. buy a couple cans of Gunk classic engine cleaner, spray down all the oily spots on your engine (WHEN ITS COLD!!!!), let it soak in, then hose it all off. now put the entire contents of the little tube of dye in the oil, and take a quick drive around town, park in the deep shade (or in a garage) pop the hood and use the UV flashlight to look for where the glowing (green or orange or pink depending on which dye you got) is oozing.

if its coming from the front camshaft seal, and blowing back, odds are pretty good your crankcase ventilation is plugged up. on a volvo, this is an oil separator box and a 'flame trap', these should be cleaned every other oil change or so. when they clog up, excess crankcase pressure will find its way out anywhere it can, most frequently by blowing one or more of those seals out.

 

That is very interesting and very helpful. Thanks so much Pierce. I will get some of that dye and see what happens. Now when you say camshaft seal, are you talking about the valve cover gasket? And it is on top of the valve cover which is weird. I just bought a new oil cap from oreilly's because the old one was just this rag covered mess secured with chicken wire. I haven't seen the new one leak while watching it run, but i suppose its possible its just a bad cap. My dipstick still tells me that i have full oil even though it appears to be leaking a bit. Those dip sticks are weird to read I am totally new to Volvos, I've only ever worked on domestic cars. Love these bricks though i don't know what it is about them exactly but they interest the hell out of me. Built like tanks and simple, but with a particular character to them.

 

Noticed you meant sealant on the valve cover gasket not oil ^

 

Hosing down the engine won't harm any of the sensors or cause any other damage? And where is this oil separator box located?

 

The place that you use Permatex on the valve cover gasket is where it goes up over the camshaft. If you remove the valve cover, you will see that it is flat except for at each end where the camshaft sticks up above the sealing surface. It is in the corners where the valve cover gasket has to make a sharp bend to go up and over the camshaft that you place a dab of Permatex,

Now when he speaks of the camshaft seal, that is where the camshaft comes out of the front of the head behind the timing belt pulley. When this seal leaks oil blows all over the top of the engine.

Regarding the flame trap, it is located between cylinder 3 & 4 intake runners. There is a hose that runs from the flame trap to the air intake. Below that hose is the flame trap and underneath that a hose runs down to the oil separator which is mounted to the engine block. This is all hard to access due to the intake manifold.

 

Yes, it is possible for the engine to run well yet have an externally oil leaking head gasket. The b230 is especially prone to this after 200k, more or less... In your case you should eliminate all other possibilities before tackling the HG. And, make sure the crankcase ventilation is not obstructed--you are on the right track looking at the oil separator. Worst case, the HG swap on a car that hasn't been overheated is quite easy.

 

Thank you guys I appreciate it. I will definitely eliminate all other possibilities before i go for the head gasket. Act would you recommend that i just take the intake manifold off if i end up replacing the oil separator? And with what Pierce said about hosing off the engine, does this ever damage any of the sensors or anything?

 

just avoid blasting water directly at the distributor cap. the sensors are all quite hermetically sealed unless they are ancient and in bad condition, whereupon they'd likely die before long anyways.

 

Before replacing the separator, I would just make sure the flame trap is clean. You can access it without removing the oil separator. Just pop off the hose that runs to the air intake and you should see the flame trap just beneath it. Remove the short vacuum hose from the flame trap and you should be able to pull the flame trap up. Clean it good with carb cleaner making sure all of the holes are clear.

On the three 240s I have had experience, I never had a clogged oil separator.

 

I will do that this weekend thank you for the advice! I have been paying a lot of attention to the engine while its running and it looks like the majority of oil is in fact leaking from the valve cover gasket, so I will be ordering one of those. I am still trying to keep my eye out for that ultraviolet dye to track oil leaking from the engine. I am out here in Hawaii it can be tricky to find things like that.

 

i had to ask for it at the local autoparts store, it was a behind-the-counter item.

 

Pierce you were absolutely right. The flame trap was completely clogged and the oil seperator box had a crack in it and was clogged as well.

 

sounds like cam seal. if it is, do your valve hushers and a valve lash adjustment while you have the cam belt off! Meaning, pulling the cam to do the job instead of depressing the buckets with a tool and trying to pop the shims out. I got a micrometer from NAPA for $50 to measure the old shims and then do a little bit of arithmetic. do you know what I am talking about?

 

I have actually never done anything like that. I recently removed the intake manifold to replace the oil seperator,(egr in the way) and flame trap and all the oil stopped leaking. It was coming from the valve cover gasket, after I replaced that no more oil leaks

 

Seems like getting the PCV system cleared up took care of the excess pressure and stopped the oil leak, so what's the need of messing with the cam seal?

Revolve is talking about adjusting valves, replacing hushers (never worth it), etc.
What's the need for all that?

 

No need for routine maintenance on a car with a history of being held together with rags and chicken wire!!! Just run it into the ground.

Well I see you did valve cover gasket. Should of measured valve lash while it was off. Saves you $ on buying another gasket.

 

yeah, if you have to take the valve cover off, you really should measure your valve clearances. there is no 'adjustment', they have to be shimmed. odds are VERY good they won't need any shims at all, most never do, but its still good to CHECK and verify this.

 

word! Specs are even on the emissions sticker in case you suck at the internet.