Amazon: Bent Push Rod

[142 Guy]

Originally Posted by ColoradoAmazon

My oil pressure gauge is connected at the stock OPS location just below the oil filter with a "T" fitting. If my gauge is reading pressure I'm thinking my oil pump is working but maybe not working properly.

I have never had the head off. But I'm thinking that might be the next step since there just isn't any oil coming up to the top.

I'm just wondering if it's worth pulling the oil pan off and inspecting the oil pump before I bite the bullet and pull the head off.

How much pressure are you measuring when cranking the engine? When I had my pump failure, my initial test during cranking showed about 7 psi which then dropped off the face of the earth. During cranking on a cold engine with 10w30 if you are getting 15 psi you are probably good. Others can advise on what they measure because this is very dependent of oil viscosity. I use 5W50 so my observations may be skewed.

I am not super familiar with the Amazon; but, on my 140 you need to lift the front of the engine to remove the oil pan. So this is not a trivial task. Unless you are talking about removing the oil pump, there isn't a lot you can inspect after removing the pan unless it is something really obvious like somebody forgetting to tighten the oil pump mounting bolt or a rag that got sucked up against the pump suction screen. I will note that when I replaced my oil pump I took the original pump apart and could find no obvious cause for the low pressure problem so 'inspection' might yield nothing. If you go to the hassle of removing the pan to get at the oil pump I would just plan for replacement of the pump. The cost of the pump is small compared to the work associated with accessing the pump.

I have removed the head on my B20E to switch from a B20F to B20B head gasket and I have lifted the engine to do an in situ oil pump removal. Of the two, R&R of the head was much easier and faster - in part because you don't have to be under the car. However, in this case I would only do the head first if I was confident that I had good pressure in the main oil gallery which is pointing a finger at some kind of blockage - somewhere.

[Juular]

Agree with 142guy, getting the sump off is frustratingly awkward and requires either lifting the engine or dropping the cross member. It is possible to do with the engine jacked up on the bellhousing and the cross member lowered to the bottom of the bolt threads. Removing the head is absolutely easier.

I'm wondering if the head gasket has been installed the wrong way round, blocking one of the oil feeds.

I'm also of the opinion that leaking oil pump feed pipe seals are more likely than oil pump failure.

[ColoradoAmazon]

I have removed the head and I'm confused.

The head gasket seems to be on correctly. However the the oil passage on the bottom of the head is not there and nothing really lines up with the oil passage in the block. When I stick a wire in the oil passage at the top of the head it ends up in the head bolt hole.

1 - Do I have the right head?
2 - Can this head be modified to add an oil passage?
3 - I also don't understand how the oil gets from the oil passage through the rocker shaft stands. They all look the same, and it looks like they seal off the oil passage.

Again, your input is greatly appreciated. Thank You!

[Derek UK]

I think that when the rocker bolts are tightened down, all of the thread goes into the head. That allows oil to go up the smooth part of the bolt. If you check I think you will find the size of the smooth part of the bolt is smaller than the hole in the rocker stand. That may be wrong but that is how I have always understood it. Beware that these bolts are easy to break if you over torque them. Volvo don't quote a figure, but 25ft/lbs should be fine.
None of this gives an answer as to why you seem to have no oil supply to the rocker shaft so I'll be interested to see what you find. Everything looks very clean so crudded up holes seems unlikely. Turning the engine on the starter should show if you have oil supply but it won't prove that you have pressure and the pump feed pipe is secure. For a few years, only B20 pumps are available. When fitting them the B18 sump baffle has to be modified by cutting away a bit of the tin. If a B20 pump was fitted and an unmodified pan fitted I think that can push the pipe out of position and you will get no or reduced pressure.

[Ron Kwas]

CA;

If you were to stick a wire into the small diagonal passage terminating in the Rockershaft Pedestal (4th pic, and also shown on the Oil Sys X-ray drawing), you will find that its other end will be at that central Headbolt hole...so the path the oil takes is: In the block, up to the Headgasket surface by way of that small hole, then making a slight jog (in the Headgasket!**) to the space between the Headbolt and its clearance shaft in the Cyl Head, where it picks up that diagonal hole to the Rockershaft Pedestal.

** It is vital therefore that the web between those two holes be cut and open to allow flow!...which I cannot clearly make out on your pic...you could post a closeup of this area of the Headgasket...(yes, it's not a very big passageway!) but if this web was not cut away, it would be a dead end for the oil flow, and not allow the necessary flow to the Cyl Head...and we have just found the root cause (that would certainly explain the issue, but I don't dare say this too early, before having you confirm my suspicion!)

Good Hunting!

Edit: I now see that the web is cut, so my suspicion is not proven out, and the gasket looks to be right...but you are in the right search area...keep carefully looking and assure there is an unblocked passageway for oil from top-surface of engine into Rockershaft...

[ColoradoAmazon]

Ron: You are right. The web is cut in the head gasket.

142 Guy: I basically had no oil pressure when cranking (maybe 7psi put probably less). I had oil pressure when engine was running but it was low in my opinion (10-20psi).

It sounds like the oil pump feed pipe seals should be the next place to look. Sounds like removing the oil pan will be fun.

1 - I'm getting conflicting info on the head bolt torque. Is 25 lb/ft the consensus?
2 - The head bolts were tough to break so I'm assuming they were torqued quite a bit. Should I replace them? I'm assuming they are all the same.

Thank You!

[142 Guy]

You are correct that all four rocker stands are identical. As noted by Derek, on the third rocker stand, oil is forced up in the annular space between the OD of the retaining bolt and the ID of the rocker stand. The retaining bolt is a UNC 5/16-18 x 2.25". Make sure that somebody has not replaced the bolts with a 3/8 or larger because they stripped the holes out in the head when they over torqued the bolts as Derek mentioned. I have never had to check for this; but, if you think the rocker shaft is a new aftermarket shaft make sure that the through holes for the mounting bolt are not a tight fit around the retaining bolt.

When oil flows up that annular space around the retaining bolt it enters the rocker shaft through the hole in the shaft for the retaining bolt and then flows down the length of the shaft. There are little holes in the shaft at each rocker location to feed oil to each rocker bush. On each end of the rocker shaft there are plugs (#20) to stop oil from just pouring out the ends of the shaft. Check the area where the #3 rocker stand mates with the rocker shaft to make sure there is nothing obstructing the flow at that point. Do the Ron test of running a wire down that passage from the base of the rocker stand to the head bolt hole to make sure something is not jammed in there.

If there are no obstructions, as a minimum test I would crank the engine to confirm that you are at least getting flow out the top of the oil gallery hole in the block that is supposed to supply the rocker assembly. As Derek notes, that does not mean that you have pressure; but, a no flow / poor flow does point you back to a pump related problem.

[142 Guy]

Originally Posted by ColoradoAmazon

Ron: You are right. The web is cut in the head gasket.

142 Guy: I basically had no oil pressure when cranking (maybe 7psi put probably less). I had oil pressure when engine was running but it was low in my opinion (10-20psi).

It sounds like the oil pump feed pipe seals should be the next place to look. Sounds like removing the oil pan will be fun.

1 - I'm getting conflicting info on the head bolt torque. Is 25 lb/ft the consensus?
2 - The head bolts were tough to break so I'm assuming they were torqued quite a bit. Should I replace them? I'm assuming they are all the same.

Thank You!

The head bolt torque on a B20 is 61 - 68 ft-lb. The bolts are not torque to yield so they do not automatically require replacement. Be aware that there is a correct sequence for tightening the head bolts (check the service manual). You will nee an offset wrench for the final tightening because of interference with the rocker stand.

I have attached the parts diagram for the oil pump on the B20. The offending oil pump pipe seals that people reference are parts #20. From the diagram you will see that the seals are retained by a bulge formed in both ends of the pipe. Take it from someone who has had to push the oil feed pump in to place. There is no way either seal is popping out past that bulge. Lots of silicone grease was required on the seal to facilitate installation. On my car the clearance between the OD of the bulge and the ID of the receiving hole was so tight that when the pipe is in place you can't see the seal at all. That seal ain't coming out once it is in there. If the seal became torn during insertion or the seal is the wrong size or they forgot the seal during installation that could all lead to leakage problems at the pipe. If you are going to remove the pump so that you can check the status of the seals I would have new seals on hand. As noted, I would also install a new replacement pump while down there; but, enough of me barking about that one!

[Derek UK]

See newer post.

[Derek UK]

Yes, 25ft/lbs is for the 4 bolts that hold down the rocker shaft. Oil pan mod shown here.
https://www.youtube.com/watch?v=-RVnzsGUFk8&t=127s
This also mentioned https://www.skandix.de/en/spare-part...-pump/1039578/
I've only heard of modifying the baffle. Some cut a piece out and others reshape it with a hammer. I'm sure there is a Volvo Workshop Bulletin showing the mod but I can't find it.
https://classicvolvoparts.co.uk/part...Filter_B18_B20