big oil leak while engaging reverse gear

[dahicori]

thanks again everyone for taking interest in my sick N/A D24


I really appreciate your recomendations about how to take steps in the most clear way possible
The enhanced photo is perfect!

To answer your questions Red Arrow, I never noticed excessive blowby while taking off the cap. I never tried that dipstick removal idea.

So, I'm putting away the pan gasket lead.
Now I was thinking.

- when I put pack the metal stick that sticks to the VC gasket, It could not stick right off, one of them was well bent . Would it possible that its distortion may be the cause of the failure from gasket?

- I completly forgot to tell you about what happened two weeks before I realised that something went wrong : the oil indicator was flickering, but in a very strange way - just when I was on low gear + when I would take a corner "aggresively", and I thought it could not indicate a serious oil problem.

And now i can tell you that the oil does'nt leak when the motor remains idle. Last time I put the car on the jack stands, and it started to flow when i started to give it more revs...

would it be an oil pressure problem..?

But for now, I will listen to your avices and start an advanced cleaning!

edit : V8volvo, Sorry in advance because it will sound stupid, but the word "stud" is unclear to me in the mechanical vocabulary. I am not so sure to what you are referring to.

[RedArrow]

The metal sticks that hold down the valve cover, are made to be `bent`, this way they hold the cover better and more equally when the nuts get torqued down.

When you reinstall the metal strips, clean them first (they often hold sand and oily dirt) then make sure the two ends of the banana are in the UP position, pointing to the sky, while the middle area with the hump should be facing the ground/cyl head.

Also, the `studs` v8volvo mentioned are the threaded `bolts`in the top of the cyl head. They are what the valve cover nuts will be clamping on. Before you even place the valve cover on the studs, make sure these studs are all tightly screwed into the cylinder head and confirm that none of them are loose (but don`t use grabbing pliers to check this bc that will hurt the thin -and 35years old- threads). If you happen to find one of them loose, use two nuts tightened against each other and drive the stud in all the way. This is only important if you have a loose stud because otherwise the `shoulder` of the stud can push the valve cover up at the particular stud and that would result a bad seal of the gasket and in some cases it would let oil leak out (as v8volvo also suggested).
Note: not all d24 motors have the same kind of valve cover stud, I believe 2 or 3 variations exist. Greenbook mentions this at some point. If I find it, I`ll take a snapshot for you. The idea is that before you install the valve cover, you do these `safety` steps to make sure it won`t leak because of a loose stud pushing the gasket `up`.

Follow the tightening sequence which is found in the Greenbook manual, I like to do it in 3 stages and arrive at the final torque (very low torque btw) only at the last round of tightening. This can help making sure your valve cover is held very well and with equal torque on each and every nut. It`s nice to lay the new gasket on a perfectly clean top surface of the cylinder head and I usually achieve that using brake cleaner sprayed on a lint-free microfiber towel (or papertowels) then use my fingers to work old dirt, oil, or corrosion from studs etc off. Petrol works too or diesel fuel but none should end up in the motor oil for obvious reasons. Remains of diesel also need to be wiped off well. In case of rust, don`t use a wire brush because dirty particles or even parts of the wire can land in the motor oil, then ... Also worth inspecting the inner surface of the v.cover itself, check for corrosion (at the edges, also the sealing surfaces `above` the gasket. Wipe that entire area clean).


About the oil leak you have.
If you think it was the valve cover then the new gasket and properly tightened nuts will cure your oil problem.

(If it was not the valce cover, Can it be the rear seal? It could be but we don`t know for now, so don`t think of it for now. What makes me think of that seal? You mentioned that your engine leaks more when RPMS are higher than idle, cornering, or on jack etc.) Good news is that in your pictures the visible leaks are at a higher spot--- my bets are on the valce cover.

off-topic question: do you consider checking your valve clearances too, since the v.cover is already off?

[dahicori]

Ok, I understand now! Your greenbook seems way more precise than my revue technique , I can not find a specified torque for the VC.

If the culprit is the rear gasket, It looks like it will be a difficult operation for a beginner, moreover when done without a car lift, isn'it?

Yes, I thought about it, but I dont hear any weird click , and the motor runs very happily. I already checked the clearance of the rocker arms on a basic 4 cylinders - gasoline, but I suppose it will require some specific tools on the volvo !

[dahicori]

Hello everyone.

Some fresh news to start with: The VC leak is no more a problem and it was definitly the main culprit.

My mechanic spotted a second leak. Just around the crank pulley around the pan gasket.

I definitly dont loose much oil with but this involves some silly complications like I cant park the car in front of the house, which is a pain in the ass when it comes to use the brick for the "mini-fret"!

He told me that gasket is one the the worse operation to be done on this car : it involves removing of the all timing ....he spoke about 15 hours of work, and he cannot do it for the 4 following months as he has been through serious hands condition.

Now I feel depressed about it...what do you say? Has anybody already experimented this operation?

[RedArrow]

Maybe you could contact the french member Michaelovich here? He also has a YT channel.
https://www.youtube.com/watch?v=lXT-...L&index=5&t=0s

[v8volvo]

Originally Posted by dahicori

Some fresh news to start with: The VC leak is no more a problem and it was definitly the main culprit.

That is good news! Nicely done.

Originally Posted by dahicori

My mechanic spotted a second leak. Just around the crank pulley around the pan gasket.

...

He told me that gasket is one the the worse operation to be done on this car : it involves removing of the all timing ....he spoke about 15 hours of work, and he cannot do it for the 4 following months as he has been through serious hands condition.

How big is this other leak and is he SURE it is coming from that area of the engine? Can you show a picture of what it looks like?

And does he think it is from the oil pan gasket, or the oil pump/front cover gasket, or the front main cranshaft oil seal? Those would be the three main possibilities for where an oil leak in this part of the engine could come from. The second two on that list would require the engine timing system to be taken apart, yes. But none of them are really that terrible of a job. Is the timing belt getting wet with oil? That would narrow it down to the crankshaft oil seal.

The hardest one of the three is the front cover gasket since that one does require the whole front of the engine (timing parts) apart plus the oil pan dropped, tough to do in the car, but can be done if the crossmember is lowered. ngoma had a writeup here of the procedure somewhere from when he and I tackled one together years ago on a 900 series, with some pictures, you might be able to search for it and find it. If you work very carefully you can do it without having to completely retime the engine, by checking IP timing before engine disassembly with a dial indicator and then confirming after reassembly that it has not changed at all. That can save a little bit of time, as long as the person doing it understands exactly what is going on.

But first task is to figure out exactly where the leak is coming from and figure out a plan from there. And there is still a chance it is residual coming from the valve cover gasket leak! You might need to wash the whole engine to make sure you can find the source.

The idea of looking up michaelovitch is a good one, he seems to not be on here as much as he used to be but he would certainly be a good connection to have if you are anywhere near him.

[dahicori]

this leak in not that big but still a problem to be solved for sure!!

I'll try to take a clean picture tomorrow or the day after ( I have a foot strain)

He definitly mentionned the front cover gasket. He told me the easiest way to dot it would be to take out the block from the car, but he added that by doing so, I will simply destroy the wiring harness as all the plastics and wires are rotten (car parked in a garage, but still didnt run for 10 years)

I will try to reach mickaelovitch, I know he lives kind of far from my place (France cannot stands comparison with US when it comes to dimensions, but still we can have long trips inside our borders )

[v8volvo]

Originally Posted by dahicori

this leak in not that big but still a problem to be solved for sure!!

I'll try to take a clean picture tomorrow or the day after ( I have a foot strain)

He definitly mentionned the front cover gasket. He told me the easiest way to dot it would be to take out the block from the car, but he added that by doing so, I will simply destroy the wiring harness as all the plastics and wires are rotten (car parked in a garage, but still didnt run for 10 years)

I will try to reach mickaelovitch, I know he lives kind of far from my place (France cannot stands comparison with US when it comes to dimensions, but still we can have long trips inside our borders )

I think you will want to check carefully to confirm that is where the leak is. He is right that it is a pretty serious job to repair it, and in some ways, removing the engine might be the easiest way. He is also right that that might do some damage to a fragile old engine wiring harness -- although on these old diesels the wiring is so simple that repairing harness problems is not that big of a deal, especially on a 240 with a non-turbo engine. There are only about 6 wires total in that harness anyway so you could even build a whole new harness from scratch in just a few minutes if you had to.

However, is this a small, slow leak or is it a very large leak where oil is flowing rapidly out when the engine is running? The front cover holds *pressurized* oil inside the engine, not just low-pressure oil, since what we are referring to as the "front cover" is actually the oil pump housing. The only times I have ever seen that oil pump gasket leak, it has been in a way where pressure is escaping and this results in a very fast leak. That was the case, for example, for the one that ngoma and I replaced years ago with the engine still in the car. It had a crack in the gasket on the pressure side, and the leak was so bad that the engine could only be run for a few seconds at a time, or else it would have pumped all the oil out onto the ground!

If what you have is a slow leak, where it's just a little wet, then I still think you might be dealing with a different source that is running down to it. Like the valve cover gasket.

[dahicori]

thank you for the reassuring analysis! I can confirm that it is a small leak : the level has barely dropped and I drove 150km bw the oil add and the check. But still, it is real dirty and on a big drip, i will for sure notice that this problem is to be taken seriously.

Also one "good news" : power steering became very very hard two days ego. oil level was OK when I bought the car. The reservoir was totally empty, the white ATF oil must has been mixed with some dirt or engine oil and maybe it was responsible for the little oil pond I discovered weeks ago. Do you know what is generally responsible for that can of leak? I hope that my steering rack is okay. I heard it s a pain in this ass to change it!

[ngoma]

Originally Posted by dahicori

power steering became very very hard two days ego. oil level was OK when I bought the car. The reservoir was totally empty, the white ATF oil must has been mixed with some dirt or engine oil and maybe it was responsible for the little oil pond I discovered weeks ago. Do you know what is generally responsible for that can of leak? I hope that my steering rack is okay. I heard it s a pain in this ass to change it!

Sorry have to keep repeating: To find any leak source (unless it is totally obvious) you must CLEAN WELL THE AREA. Clean until it is DRY. NO traces of oil, grease, dirt, or other fluids. THEN you can observe where the leak comes from.

FOR YOUR CURRENT SITUATION with a PS system leak that means clean the PS pump, the hoses, and the rack. Then you can describe to us what you see. We cannot tell you what is leaking otherwise. Thank You!