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I am attempting to replace the PCV oil breather separator box on a 1994 940 turbo.
Question -- Is it possible to do this without removing the intake manifold? If so, how is this done? The FAQs suggest that it is, in fact possible -- but I can't see it.
Having removed nothing I am tantalizingly close to doing so, but I am now in a bind -- I have obtained access to the PCV box, removed the 2x 12mm bolts holding it down, and 2x 10mm bolts securing the base-plate with the wiring harness in front of it. The PCV breather box now lifts up off the block just less than 1 inch but I can't rotate it or tip it far enough to get it out of its housings. Afraid of shattering something. Is there a trick to this?
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posted by
someone claiming to be rjk
on
Sun Nov 4 15:48 CST 2018 [ RELATED]
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With 220K on that HG in a turbo you are probably on borrowed time IMHO.
Granted, if the car was treated gently by a little old lady from Pasadena it could very well last that long but...the higher heat and associated expansion/contraction due to the turbo will degrade the head gasket to the point it will start leaking something, somewhere, eventually. Oil, coolant, combustion, you name it could go into any of the aforementioned or out the side. Any blackness in the overflow tank? You mention oil under the intake mani (could also be valve cover leakage).
If you have the time & energy doing a HG is not overly difficult but you will want to check the head carefully for flatness before you reinstall it. If I remember correctly, it should not be more than .0005" off either longitudinally or traverse.
If the engine never overheated it may still be flat, if it did overheat at some point the head is probably in need of a shave.
Good luck!
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>If you have the time & energy doing a HG is not overly difficult but you will >want to check the head carefully for flatness before you reinstall it. If I >remember correctly, it should not be more than .0005" off either longitudinally >or traverse.
The information included in the FAQ's concerning head warpage is as follows:
Head Surface Warpage. [Scott Cook] Whenever you remove the B230 head, check it for warpage:
Using a metal straight edge and feeler gauges, measure the short way across the head, between the cylinders and at each end. The maximum distortion specified in the Volvo manuals is 0.25mm (0.01"). Above this and you must machine the head (but see below).
Measure diagonally across the length of the head. From the right rear to the left front and vice versa. Maximum distortion in this dimension is 0.5mm (0.02").
If the distortion or warpage in the short dimension across head is 0.5mm (0.02") or more, or in the diagonal longer direction is 1mm (.04") or more, the head must be replaced, not machined and reused.
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Dear rob2volvos,
Hope you're well. Yes! Removing the oil breather box (OBB), without moving the intake manifold, requires: (a) the remover to have "small" hands and (b) removal of the hoses go to the idle air control valve (IACV) as well as the IACV.
Before doing that, be sure you have a replacement OBB "O" ring (Volvo Part #949659, about $7 at a U.S.-based Volvo dealer).
Further, before swapping the OBB, re-tighten to very snug, the hex bolts that secure the OBB. Then, use brake cleaner to flush dirt and grime away from the area around the OB. This will ensure dirt and grit don't fall into the oil pan.
Once you've cleaned the area around the OBB, unbolt the OBB. With the IACV hoses having been removed, you should be able to rotate the OBB towards the front of the engine and pull the OBB towards the front of the engine. If you still can't get your hand into that area, remove the bracket on which the IACV is mounted.
Then, remove the in-service OBB "O" ring and replace it, ensuring that it seats into the recess. When you emplace the new OBB, be careful not to displace the hose beneath the OBB opening. The best way to avoid displacing the hose is to position the OBB directly above the opening, and gently insert the OBB's bottom nipple into the hose opening.
The hose drains into the oil pan, the oil drips from the OBB. If this drain hose drops into the pan, it is needful to drop the oil pan. That is a panful (pun intended) operation: the engine has to be freed from its mounts and then lifted an inch or so, to enable the oil pan to clear the oil pan cross-member.
Hope this helps.
Yours faithfully,
Spook
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Thank you, Spook for your generous and detailed answer to my question.
Just for completion sake I thought I'd share my experience on removing the PCV oil breather box (OBB) from my 94 940 turbo wagon.
I removed the main air intake, plus IACV hoses and IACV from the car. And just for fun I removed the throttle body (3 bolts + gently unclip and persuade off the ball joint thingie). Easy.
But still, having unbolted the OBB and unhooked it from the 2 x 10mm fasteners at the base, I could not remove the OBB from the car without forcing or risking breaking it. I found that the key move was to unhook the coolant hose going into the cylinder head just above the shoulder (toward the rear of the car) of the OBB. That was not particularly easy because you can barely see the target. To do this, I was balanced on a cinder block from the passenger side, leaning into the engine bay, gently levering the thing off with a foot long thing screwdriver down between the fuel rail and the cylinder head. Gosh, one really needs a lot of patience if one does not really know what one is doing on these cars, doesn't one?
With 220K on the car, and signs of an aging head gasket (evidence oil under the intake manifold), I'm wondering whether, having torn the thing down this far, I should go ahead and do the HG "while I'm about it". Any comments on this topic welcome ...
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Dear rob2volvos,
Hope you're well. To remove an oil breather box (OBB) I've never removed the heater hose, that connectes to a nipple on the heard. That may be because I was able to position my hand, so I could grasp the OBB and moved it.
While I've changed heater hoses - laying on a thick board that spans the engine bay - that was because the hoses needed it. Volvo brand heater hoses will last for about 15 years, if the car lives where average temps are not tropical or desert.
When comes the time to remove that heater hose, see the FAQs for a method, that involves slo-o-o-o-o-o-owly deepening a shallow, longitudinal cut in the hose, and then peeling the hose from the nipple. One has to cut slowly and not too deep, to avoid scoring the nipple, and so causing a leak.
As to the time needed to do work on a 940, consider how much more time would be needed to work on a front-wheel-drive car, where everything is crammed into the engine bay!!!
Hope this helps.
Yours faithfully,
Spook
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