2.0 8V bottom end rebuild (by idiots)

[eyesoreracing]

We made some big diagnostic progress on the knocking noise this weekend.

When I reviewed the videos I had in my phone, I realized there were two different knocking noises. The most severe was this:

https://www.youtube.com/shorts/lScIqDFrkNI

that's the noise that made me turn around and go home.

Originally, I thought this second knocking noise was the same noise:

https://www.youtube.com/shorts/R3RBycGQLAY

But listen back to back and they are clearly different.

We finally tracked that second noise down to the AC compressor. I never knew the AC compressor was even turning on. The fact that it was on intermittently explains why this noise came and went (usually with engine temperature, but maybe not always?)

The first noise may be rods, or it may be a more severe stage of the AC compressor's failure. This is unclear and may always be. We know for sure that the oil pump's pressure relief piston had some marks and didn't move smoothly. And we know the rods show some marks from making contact. But all four rods look identical and that first noise sounds like a lower frequency than four rods would make. Sounds like one rod at the most. Maybe it was one very unhappy piston in the compressor.

Anyway, to address your question, I hand-sanded any part of the journals that looked like it needed work using something very fine. More than 1000 grit, but I don't remember exactly what.

Currently, cold idle is 70 psi, hot idle is 20 psi. Plenty of pressure to keep the bearings happy.

Meanwhile, we found this problem while troubleshooting the AC system. A bad compressor is part of the problem, but probably not all of it. We suspect the control unit may be flaky, wanted to pull this panel out to look for anything disintegrating on the circuit board:



Any advice on how this comes out? I don't want to pull to hard...

[eyesoreracing]

Suspension question:

While we were on the lift troubleshooting the AC/knocking noise, we noticed the go-down hose (the return hose on the suspension where the fluid goes when the suspension goes down) was broken, and pissing suspension juice all over the wheel. We spliced it back together temporarily, but I'd like to find a more reliable fix.



Looking at the fitting where the go-down hose comes out of the front strut, I can't figure out if the hose is one piece of rubber all the way into the body of the strut or if it can be pulled straight up and separated from the lower part that's clamped to the strut. I'm afraid to pull to hard in case I break something hard to fix.

[Dieselman]

Front suspension return hose is one piece, p/no 95050399. They do wear out and are held on with a stainless steel click-clip, p/no. 96127591, which are re-useable if the original Citroen Click-clip type.

The heating/ventilation control unit comes out after the knobs are pulled off. Use flat pliers to gain a good grip and pull swiftly. The panel front has screws.
If you want to stop the A/c compressor, use the "A/c Stop" button. The Led being on stops the compressor.


Good to see the oil pressure is sound.

Crickey, that compressor sounds bad, I've known a VW one lock solid after a piece of the internal nut broke off.
The second noise may well be the hydraulic pump, do you know the condition of the regulator sphere? A flat regulator sphere, lots of fluid demand, or air in the pump will make it noisy. New fluid can make a surprising difference.

To isolate the noise either use a mechanics stethoscope, or slip the auxiliary belt off.
To me, the engine itself sounds fine.

[eyesoreracing]

My first thought was the hydraulic pump (you can see the belt is slack in the second video). When we finally removed both belts the engine sound was very smooth. I only noticed the AC was turning after I reinstalled the ribbed belt, so pressing the AC off button fixed it immediately. A new compressor is on the way...

I believe Sean replaced the regulator sphere just before he blew the head gasket. That may have saved the car, as the suspension working correctly gave us to motivation to rally everyone to help fix the engine.

[eyesoreracing]

Front suspension return hose is one piece, p/no 95050399. They do wear out and are held on with a stainless steel click-clip, p/no. 96127591, which are re-useable if the original Citroen Click-clip type.

how do these clips work? Are these the same things we're seeing being used as hose clamps? We haven't been able to remove OE hose clamps without cutting them off and replacing them with screw clamps.

[Dieselman]

Don't dispose of any Click-R clips, they generally work really well and have uniformly round clamping force.

You can buy special pliers to undo and refit them, but I have used side cutters, or carpenters pincers, which work as well, sometimes better.
I have even used regular flat pliers combined with a small screwdriver shaft.



To undo use the pliers around the hook section to unclip the hook with the blunt edge against the tab, under the hook. Often there is a pressed protrusion on the back of the hook to hold the pliers jaws against, sometimes not.
Jaws around the hook, squeeze to take the tension off then pry the hook off the tab.



To refit, ensure the hook is well formed to return back onto the tab easily, then using the chiselled edge of the pliers against the tab, squeeze and press the hook into place.

If you mean the hose clips that are just a serrated band and pressed down clamp, you cannot reuse those, as you say, hack them off and use new clips.

[Dieselman]

When we finally removed both belts the engine sound was very smooth.

I believe Sean replaced the regulator sphere just before he blew the head gasket. That may have saved the car, as the suspension working correctly gave us to motivation to rally everyone to help fix the engine.

Good news, you are just catching up on a few years of neglect and have done a great job of not only fixing the issue, but ensuring it won't happen again . Any video of the engine noise sans auxiliaries?

Did you try using an engine stethoscope? It would have isolated the noisy component.
As your video demonstrates, modern engines transfer noise and a noisy auxiliary item bearing often sounds like terminal engine failure.

I would probably have stripped the compressor before condemning it, that noise sounds like a drive-shaft bearing or the pulley contacting the compressor body. Your compressor doesn't look very old.
The, previously mentioned VW one that jammed solid was a friends car, we stripped the compressor, found a chunk of the flange of drive shaft nut had broken off and jammed the mechanism, removed the offending piece, rebuilt the compressor and had it gassed and it outlived the rest of the car.