Amazon: Post-Rebuild B20 - Coolant Leak

[gothamus]

The source of the oil is the valve cover. The engine is slanted slightly upward toward the front. The very rear right side of the valve cover gasket area has some pooling. I thought I had it tightened down sufficiently. But I will give another turn.

[Derek UK]

The valve cover retaining screws only need a light hand tightening to make a good seal. Factors otherwise are a bad gasket or more usually the sides have been distorted by overtightening. Get the cover on the bench and check the screw hole areas with a straight edge. More than likely they will be belled out. Carefully flatten with a small pin hammer and a piece of steel rod as an anvil. The whole length of the cover should be flat but the screw areas are the usual problem. Have a look in your local parts shop for Chev V8 rocker cover spreader plates for these screws. V8 will mean you get 2 sets. They are a wide triangular shape but look for slim ones that tuck in behind the raised lip on the edge of the Volvo cover. Fit new gasket dry or with a bit of grease applied with a finger. No sealer/Right Stuff needed.

[gothamus]

I’ve got one of those aluminum valve covers. With this rebuild I bought some of those fancy chrome hex screw-one, don’t know what they are called. But they aren’t any good. They have this 2 sided screw. One side into head and then you screw this chrome cap on. Neither side of that screw secures into head. It was a bit small and kept coming out part or all the way. I now have 5/16 hex bolts. I’m have assumed the aluminum cover shouldn’t be prone to bending as the original. I will follow your advice to check its flatness.

I don’t recall what gasket I bought some time ago for the valve cover, but it might be the problem. It’s green and seems like a fiber material. I’ve had it for a year or 2 and haven’t found my receipt. I saw some of the pooled oil at the rear was kind of green! That’s disturbing. I’m probably going to buy a replacement this week. Cork. What’s wrong with cork? I’ll get one of those.

First half of today I continued to have problems starting the car. Mis-firing, kind of a pop. Strong sense that it may be carbs, because it’s rhythm and sound didn’t seem like anything but fuel. If the petrol is good then mix may be weak or fuel level. I did a tear down of carbs in situ. It was dirty, you would think a few years running. But I was setting everything from scratch to eliminate the issue or see if the symptom changed. Just as I was giving a final wipe to second piston I noticed the needle had slipped out about an 1/8”. Screw was a bit loose. I corrected that. Verified the other was good. Completed that job and she cracked right up. Running excellent I put a good mile in, varying throttle and power. Temp is high but not to the top this time. I’ll be running some more mauled tonight. Flush radiator at some point. Promising. I’ll check that piston later to be sure there isn’t a repeating problem.

[Derek UK]

The out of position carb needle was obviously a problem so that should fix several issues. The normal situation is you can't get the needle out without damaging it even after loosening the screw.

[gothamus]

Running much better. Temp higher than the halfway point but not to the top, even when idling still.

I am wondering about the sound out of exhaust- when driving and getting past about 3500 RPMs, under acceleration, the sound from of exhaust becomes very deep and like a boom. Instead of a consistent increase to stronger booming, this sound could lead to a roar like a canon. My exhaust tends to a deep sound, but this is much deeper than I recall and I back off. Only a couple of miles driving so far and I'm anxious of putting a lot of pressure on the engine in the first ten miles. I'm only mixing up the driving conditions. Timid driving, maybe, but why not right now? Perhaps I should consider the progressive timing? Or the carbs mix is too rich?

Maybe I can run my headphones out the back window and record something.

[Derek UK]

"Normal" temp gauge position for the needle is a fraction under or just touching the right hand of the 2 white central indicators. It might go just above that indicator if stuck in hot traffic but should come down again once you get on the move. 90º in NY will put it to the test.
What exhaust system do you have? Is it standard Volvo or aftermarket? Check for leaks. A gloved hand over the outlet will show them up easily. If you have the Volvo cast iron exhaust manifold, the joint to the pipe can leak and burn out the gasket. Retainer nuts not so easy to tighten, especially the one near the block.

[gothamus]

Running the engine in despite heat, humidity and in-law bereavement things. Night time running gives me more wiggle room on the hot end of the gauge. It’s either getting better or my gauge is flaking out because it went too hot too often. One time it registered in the nice zone when the engine had not yet done so. I became suspicious, pulled over and checked with my little hand hold infrared thermometer ( not the best quality, not worst) and the engine by thermostat at rear was 210f/98c degrees.

I advanced the distributor a bit forward and the throttle response improved markedly after having been hesitant. With that improvement something something had to give. No sooner did I think it and as I pulled to a stop light I heard a “ting”, felt something in the brake pedal and the car stopped promptly.

I was able to drive with it Lund up in order to get the car closer to home. I was less than a mile away. I think it’s the drivers side rear drum since that is hot compared to than the other.

All winter waiting to be used, I’m not surprised. I rebuilt the braking system awhile back. So I’ve got the tools to address it, thankfully. Going to pull the drum shortly, unless I see something.

[gothamus]

"What exhaust system do you have? Is it standard Volvo or aftermarket? Check for leaks. A gloved hand over the outlet will show them up easily."

I have Simon's 4-1 exhaust. I wish I had gotten it wrapped before I installed everything. It's pretty hot. It gives a deep baritone sound. What stands out to me is progressing through acceleration, a little more aggressively, in 2nd or 3rd gear it sounds louder, like the flames are going to shoot out the back (illustrative description, not actually flames, just really opened up). Gotta record this on the phone.

Temp seems steady, just over the right hand line on the gauge. When I park and check the temp I was measuring 190 to 210 degrees at various points on the engine- by thermo, at plugs.

[gothamus]

The engine is performing pretty good but I am watching the temperature closely. The gauge was right in the sweet zone the other morning, which makes me distrust the gauge. I didn’t have my little thermometer so I couldn’t get some comparison.

I took her on the BQE, a ring road not far from me in Brooklyn, to get a mile of highway running. Nothing blew up and driving performance was normal. When I got back I found a lot of oil had escaped out of the passenger side of the engine. Either the sump gasket or filter seal. There was some tightening that could be done but I’m concerned about the amount of positive pressure. If things are good elsewhere it should mean sump bolts were very very loose, to my understanding. I’m removing the nipple on the manifold just to be sure the small hole is not clogged and there is somewhere for gases to escape to under engine braking conditions. I’m not sure how large that opening should be. I saw a table of sizes for different B20 engines but I haven’t been able to find that page again. 2mm? I have a one way valve on the flame trap, so no escape from the side.

Since I lost a lot of oil I went ahead and drained what was left and changed the filter. If things go well I shouldn’t need to change oil for another 500 miles.

[blueosprey90]

You're a very brave soul to be test driving on the BQE.