OPRV Questions

[ScoobySteve]

I've done a search and now I'm even more confused.

I just took out my oil cooler for resealing and cleaning. Obviously, had to take out the OPRV. I'm on an '86 NA. From the pictures that have been posted, I have the 1-piece retrofit into earlier blocks valve. It looks just like that picture. Though, I would actually call it a two-piece design.

On mine, when I pulled it out my buddy remarked how the valve looked "bent." Well, it turns out mine has a fair amount of pivot between the two pieces (thread+bolt head and valve body). Is this normal and allowable? The two pieces are held together firmly, so it's not like they are loose and falling apart.

Also, I don't have new o-rings. My outer one looks just fine and I had no oiling problems before teardown.

I bought the OPRV alignment tool for putting the housing back on and my first attempt resulted in a very firmly stuck alignment tool. I had to loosen all the bolts just to get it out with a little prying and then re-torqued. I'm hoping this is normal and I didn't wreck the alignment.

Lastly, and this may be because it was 2AM and I was tired, I'm having a lot of trouble getting the OPRV back in. It slides in just fine, but the pivoty nature of the threads and bolt head seems to make it really want to crossthread.

I started this job with normal oil pressure and no mixing of coolant and oil (I have the head off for HG so I figured accessibility would never be better) but now I'm afraid I'm going to screw something up and end up with problems.

[mikepellegrini]

I've only dealt with the old-style OPRV so I can't say precisely what a new one should look like. The old ones are just a holder, a piston and a spring. The piston moves in and out, held by spring tension.

I've never looked at a new style, but it's gotta be the same - very simple.

If it was working before you took it out, I'd hope it would still work when you reassemble it.

The only common problem I'm aware of (in installation) is binding. As long as the OPRV slides in and out freely, you oughta be okay. You just have to play with the cooler housing till you get it in the right spot.

[bazar01]

Make sure you build the oil pressure up by cranking the engine with the DME relay out of the car before you fire it up. You really cannot mess it up.
If its binding in the closed position, the oil pressure will be very high and will just blow out the oil filter seal.
If it's binding and keeping the OPRV in the open position, you will not develop oil pressure while cranking the engine.
With these two conditions, all you need to do is re-align the cooler housing to correct the problem.
Good luck!

[HondaDustR]

It is normal for the 1 piece to be "flexible" like you describe. It's actually supposed to pull apart there, allowing you to replace the internal o-rings. I also think the o-rings get messed up when you do pull it apart. It's like $10 for new ones, but I didn't repalce mine even after disassembling the valve, and it never had a problem.

The 1 piece OPRV is pretty finnicky about the alignment. It is basicly the same idea as the old 3 piece valve, only shrunk into the inside of the valve body. I don't know exactly as far as using the alignment tool, since I used the OPRV as the alignment tool. The factory manual states that the housing must be installed aligned exactly so, which will allow the alignment tool to slide out. If the housing gets cocked while tightenning the bolts, it will pinch the tool in the hole and make it stick. I'd say check the tool often while slowly and evenly tightenning down the bolts, making sure the alignment tool doesn't get stuck.. Maybe wiggling it in the hole while tightenning each bolt a very small amount at a time may keep it straight while the gaskets, etc initially compresses.

The bad thing about using the OPRV to align the housing is it can still allow a slight bit of misalignment. This will cause the OPRV to cock slightly at the joint. I found out because the oil pressure at higher rpms was a bit higher than normal after I did the job. I took the OPRV out and noticed a slight bit of resistance as I screwed it back in. After messing with the valve, I found that cocking it at the joint limited the piston travel about 1-2 mm, which limited the range of pressure regulation and caused the oil pressure to rise across the higher rpm range, and would nearly peg the oil pressure guage at redline. I wasn't about to take it all apart just for that and just left it that way. What the heck, the bearings will last longer, it wasn't blowing out any oil seals, and it slowly improved over time anyway. The valve could possibly get stuck open or be limited much more than that if not aligned correctly, so it would be good to make sure it's right.

I found that pulling the fuel injector connectors off was easier than climbing under the dash and trying to fanagle the relay out, but that may just be an early car thing.