Probably already know it’s bad, but how bad?

Discussion in 'Tech Discussion' started by 8888, Jul 29, 2018.

  1. PrairieDrifter

    PrairieDrifter Full Access Member

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    Its not exactly the pcv valve, but it is apart of the same system. Rubber that is really hard and dry is extremely difficult to work with, it has no give after its swelled larger than the hole its in. You could try to somewhat carefully pry it out, if pulling really hard on it doesn't work great.
     
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  2. bucket

    bucket Super Moderator Staff Member

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    Yeah those rubber grommets can turn into more of a hard plastic over time.
     
  3. 8888

    8888 Full Access Member

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    Thanks for the info. It came out a little bit ago with some really hard twisting and pulling. Soaking overnight must have helped, or I just gave up caring if it broke or not.

    I then took the valve cover loose from the head and a decent amount of oil came out the bottom side of the head, back by the brake booster. It was clean oil so it is whatl I added at the recent oil change, and this is the side where I see the oil at the exhaust pipe flange. This is sort of what I expected, even more so after seeing the passenger side condition, so I'm actually glad to see the oil there.

    It appears I need to remove the AC compressor and bracket to get the valve cover off/out the front side of the engine so I'll work on that later today or tomorrow. I'll clean it as I did the passenger side, be sure the oil returns are clear, and reassemble.

    I'm cleaning up everything and repainting as I go so it's taking longer than it usually would.

    Have to deal with cleaning up some baseboard heater wiring so we can install new trim before getting back on the Suburban. Gotta keep up on the honey do list to spend time in the barn with PBR and projects, haha.
     
  4. SquareRoot

    SquareRoot Member

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    Haha....WTH do you keep referring to as a " donut gasket?"
     
  5. 8888

    8888 Full Access Member

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    Between the exhaust manifold and the downpipe.
     
  6. SquareRoot

    SquareRoot Member

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    Ok. You lost me when you said "Few drips of oil still coming from the donut gasket".
     
  7. 8888

    8888 Full Access Member

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    Understandable, oil dripping from that area isn't something normal, haha.
     
  8. 8888

    8888 Full Access Member

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    Okay, got the valve cover off after removing the AC compressor and pivoting the AC bracket out of the way. Lots of oil pooled in the back of the head, started sopping that up. Still not sure how and why the valve cover came off which should be interesting getting it back on but cleaning will continue tomorrow.
     
  9. 8888

    8888 Full Access Member

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    Update time - used a few rolls of paper towels/shop towels/panel trim tools and a disposable drain snake attachment to clean the sludge out of the heads and the oil return holes on both sides.

    Used a turkey baster to squirt 4 or 5 loads of oil down that rear return hole by the brake booster where oil had pooled previously to be sure it drained properly. (Note to self, replace turkey baster before Thanksgiving).

    I was right that not knowing how that valve cover came off was going to get me on reassembly Had to remove some wiring harness and the metal vacuum pipe to get it back on.

    Got everything back together tonight and fired it up with sacrificial oil and filter. Started easily with a fine haze of oil smoke that continued for the 10 minutes I let it idle and a light misfire unnoticeable at higher rpms.

    One or two drips of oil from the donut gasket area on the exhaust manifold at the end of the 10 minute run which I assume was oil accumulated in there when the return holes were clogged burning off. Nothing like what I had seen before, which was a puddle on a short run, so the return hole is clear and oil is no longer backing up like it was.

    I drained the oil when hot and it had darkened significantly so I assume it suspended and drained some sludge in that 10 minutes. I changed the oil and filter and filled it with Rotella T, I use that in my Cummins and Rabbit diesels and it does a good job suspending soot so it should do well with sludge. Planning another oil change after a longer run next time (thermostat opened) and we'll see what we have.

    I still have some oil fouled plugs on the clogged return side to change/clean which should help with the misfire. I probably still have some oil in the exhaust system that needs to burn off which should help with the oil smoke haze.

    All things considered, I'm really happy with what I saw tonight. I really like the old girl, she's exactly what I have been looking for. I'm between jobs at the moment so I have to give this engine every chance to recover before thinking about anything else.

    To answer the questions about why I'm not driving it, I have two boys of driving age and a lot of cars insured now. If I put valid plates on it to drive it, I have to insure it, and I'm not in a position to pay for that just yet. My wife works for the local judge so it won't do to get pulled over, haha.
     
  10. 8888

    8888 Full Access Member

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    IMG_0983[1].JPG

    On the plus side, the engine bay cleaned up nicely so if it doesn't run better, it will look dang fine running like it does.
     
  11. 8888

    8888 Full Access Member

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    Update: Truck continues to have a very light haze of oil smoke at start but is getting better every time I start it. I imagine there is quite a bit of oil inside the exhaust manifold and downpipe that needs to burn off.

    I pulled the plug where the oil return was blocked and it was oil fouled so I replaced it with a new one. I have Rapidfire platinums installed and I know platinums doen't tolerate oil like coppers do. Neighboring plug on that side was clean. Also discovered the guy who installed the plugs didn't regap them to .035" (I understand this is the correct gap for the 5.7) and they are closer to .045" out of the box so I need to fix that.

    Truck sounds much better now, misfire is very minimal, and the oil is staying clean, but I want to run it for a while and change oil and filter once more.

    I am starting to suspect the oil pressure gauge so I want to change the sender. I've read online that the sender is above the oil filter. What is up there is nothing like the senders I've seen in the past. There appears to be a short pipe and a fitting going to the block with an acorn shaped device possibly threaded into the fitting? Sound right? It's got a wire attached to it and it's in the right place, it's just different than I expected and not what I got from Rock Auto for a 1988 Suburban R10 with a 5.7. I'll grab a photo today if needed.

    Thanks!
     
  12. DirtyDYT

    DirtyDYT Full Access Member

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    Been following this thread-great to see the continued progress!

    I hear ya on insurance. Got three vehicles registered and just don’t have the coin to add my C10 to the fleet yet. There is one primary difference: it’s just me and my 22 month old LOL

    Like the image below? Pic is of a sender found on an ‘85 454.

    Both my trucks run manual oil pressure gauges now.

    AD2F8B13-213F-41E4-95FC-4559C6440D58.jpeg
     
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  13. PrairieDrifter

    PrairieDrifter Full Access Member

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    The sender above the oil filter is for the dummy light. The actual sending unit is next to the distributor behind the intake.
     
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  14. 8888

    8888 Full Access Member

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    Thanks for the replies, glad some folks are following along.

    Yes, the sending unit looks like yours, DirtyDYT, but it's in a different position, above/behind the oil filter. I initially bought one with 1/8" thread and after I managed to get the original off, I discovered it was a 1/4" thread so I'll get that this morning and can install it. BTW, does DYT mean you're in Dayton? If so, you know Ohio rust and know why I bought one from Oklahoma, haha.

    Prairie Drifter, I had originally bought one that was supposedly for a gauge versus a light, the type I "usually" see, shown below.

    https://www.rockauto.com/en/moreinfo.php?pk=940904&cc=1301049&jsn=1

    I was told the Wells unit shown above was for the light and the acorn shaped version was for the gauge. Not true? If not, wish I would have known about the sender behind the distributor when I had the valve covers off, may have been easier to get to.

    One other question about the oil pressure monitoring system....I was doing some reading on the TBI system and one article mentioned that the oil pressure reading was monitored by the ECU and if the oil pressure dropped below a certain point, the injector pulses were cut off to save the engine. Any truth to that? The internet occasionally can be incorrect, haha.
     
  15. bucket

    bucket Super Moderator Staff Member

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    It's an old wive's tale.

    There's a sender for the gauge. There is no idiot light at all. The other sender GIVES power to the fuel pump, in the event of a fuel pump relay failure. An extended crank time to get it fired up is often because the fuel pump relay is bad.
     
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