C70 T5 smoke problem

[Vikingt5R]

Hello guys,

I have a problem with my engine B5234T3 year 98, (160,000miles)

Recently I changed the sealing paste of the cam cover and the oil pan, for a noise from lifters I discovered that the previous owner of the car used conventional paste to seal the cam cover ....
Well discovered this I disassembled it and reassembled with original volvo sealing paste, I also decided to change the sump oil orings, since I had read that they hardened and the oil pump did not work well. Also change the oil and original filter, and replace the gasket of the throttle body and the elbow since they were worn.
Once the work was finished I was very happy because the noise of the lifters disappeared completely.

My problem comes when after having done this I discover that my oil dipstick is smoking, then I test the glove and it inflates into the oil cap and dipstick .... here I worry a lot, because my pcv was completely replaced with an aftermarket kit ago
*3 months...

I begin to think that my engine generates a lot of leaking gas due to the internal wear of the piston rings for example ...

Then I do a compression test and I'm happy with the result since all cylinders have the same pressure.

After doing this test my headache starts because I don't know why my dipstick is smoking ....

I decide to go a few miles to see if the smoke is reduced, it seems that after doing a few miles less smoke comes out of the dipstick but my glove is still inflated ....

I have checked all the hoses that go to the pcv and are fine.
When I change my pcv clean all the holes.
The car has no other fault, it goes better than ever but I have smoke in the dipstick ...
Finally my ptc valve is completely clean but I am suspecting that its electrical connector is not working.


Is it possible to generate smoke on my dipstick for a ptc even though it is clean?
Or is it possible that after disassembling the oil pan and cam cover you need a few miles for the smoke to disappear?
What else can I check to find the problem?



Thank you very much to all !

[Luxobarge]

Where the PCV system goes into the engine block the channel goes through a right-angle, and this can block up with coke-crud. There's an excellent thread on here somewhere about it. You might be able to clean it by taking the PCV off again and poking a flexible wire or something down there, but the best way is to take the oil pan (sump) off again. Pity you didn't know this when you had it off recently eh?

Others may be able to add to this, but irrespective of oil consumption or smoking, you should be able to get negative pressure on the dipstick tube with a completely clear PCV system, so there's definitely a problem with it somewhere.

[Vikingt5R]

Thank you for your answer, I already know the channel you speak to me and I already knew it when I disassembled the oil pan and I did not have to clean it because I had no dirt, look at these are the photos of the channel that you tell me as I found it without cleaning necessary:
Photo: 1.jpg

And here the block holes also seemingly clean ...
Photo:2.jpg

However I am suspecting this part indicated in the photo:
3.jpg
I don't think it's the problem, but I applied volvo sealing past in this square as in the rest of the oilpan outline (as I have marked in red)
The edge of the indicated square has to go unsealed? Is this the problem?

On the other hand if I get pressure on the dipstick the only possible cause has to do with the pcv system?

[Vikingt5R]

any idea??Thanks

[ASt85]

If your PCV system was replaced with an aftermarket 3 months ago,
it is possible the rubber tubes have been reversed
it should be as shown in the diagram below.

[IMG][/IMG]

[Vikingt5R]

Thanks for your reply ,

Before my engine had the original pcv and I bought the aftermarket pcv and connected the rubber tubes the same position as the original pcv.

Do you mean that, in the aftermaket replacement, the position of the rubber tubes is different from that of the original pcv?

[ASt85]

Originally Posted by Vikingt5R

Do you mean that, in the aftermarket replacement, the position of the rubber tubes is different from that of the original pcv?

I replaced the PCV system on my 850 around 12 years ago, just before I bought a V70. As far as I remember there are different oil traps depending upon the engine type ie the 10 valve and 20 valve oil traps are different as are turbo and non-turbo models. Whilst the traps will physically fit into position on either engine variant, neither will perform correctly if the wrong trap is fitted; the pipework is different, but if you have been supplied with the wrong kit for your engine the pipework is right for the trap but wrong for the engine - you need to check your VIN or engine number against a parts list to work out which one should be fitted.

PFS Volvo have a parts guide list "filter" where you can work out which part should be fitted for your engine here
https://www.partsforvolvosonline.com/index.php
or if you can't find what you are looking for you could try ringing FRF Volvo Swansea (you'll find their number in the traders listing on the front page of this website).

[Vikingt5R]

again thank you very much for the information !!

I bought the pcv in PFS and I just checked it, buy the right one.

I think I still keep in the garage the original pcv that I replace, I will disassemble again and check how it works with the original pcv

[SteveSarre]

Hi Viking

Did you check the nipple (13 on the Volvo diagram) in the big plastic tube that goes to the turbo?

That should be clear. It is called the PTC nipple.

Steve

[Vikingt5R]

The ptc was one of the first things I checked, it is in good condition, I was surprised that it was very clean.

I update the problem, yesterday I did the following test:
With the engine running at idle the oil dipstick smokes a lot, on the other hand when you accelerate the engine and the rpm increases the smoke disappears completely, that is, it only makes smoke when the engine is not accelerating.

What I think is that when the car does not accelerate it is not able to evacuate the crankcase gases by itself, when the engine has rpms when vacuuming the intake and the turbo the gases circulate correctly.

The only thing that controls the crankcase gas at idle is the tube that comes out of the intake manifold to the ptc, so I did the following:

motor at 900RPMS (no load): disconnect the narrow ptc tube (comes from the intake manifold) and connect it directly to the fat ptc tube (comes from the PCV valve) at that time all the smoke disappeared ...

The conclusion for me is that the engine for the reason that I do not know, is not able to circulate the crankcase gases when the engine is without rpms.