Alu M52 Overheating --- Update: Sill having issues

[Chilezen]

With how many things you've removed from the engine, it's wild that that chunky stuff only showed up now.

Not sure if I'd jump straight to replacing that rad, back flush it with water, or try to dissolve that crap with some gasoline or what.

As a matter of fact, this has been appearing for a long time, as first pointed out last March.

One extra important bit of information: Every time I drain the coolant, there's always debris. This is metal flakes mostly, and some tan bits of, something. Yes, there appears to be a thread shaving on the left. And a bit of black gasket stuff (?) next to it. This is exclusively drained from the radiator, and I cleaned the pan prior to filling.

The problem has probably not gotten worse because of how frequently I drain the gawddaymn coolant. I'm only focusing on it now because there aren't bigger problems to address anymore (a small win! lol)


So yeah, despite multiple flushes, the early batch of tap water may still be causing this issue. Super flushing the rad alone might be enough. With gasoline, you say? I'll have to look that up. I've used it to clean parts before, but I never expected it to take care of calcium buildup.


I checked the rest of this thread and saw another mention of debris:

I have replaced the factory water pump with a Stewart pump. I do like the design of the Stewart, the way it directs the water up. Pretty smart.

Upon inspecting the factory pump, I found..... nothing of interest. It looked fine. No rubbing or scars on the impellers. Spun freely, quietly.



It had a little bit of "grit" stuck in with the lube around the O-ring, which I thought was odd, but I've already been seeing debris come out in the coolant, so it's no surprise to see it there.

[Northern]

With how many things you've removed from the engine, it's wild that that chunky stuff only showed up now.

Not sure if I'd jump straight to replacing that rad, back flush it with water, or try to dissolve that crap with some gasoline or what.

[jbontke]

Why do you ask about the grounding of the engine? I would say it's fine.. I don't know how much better it could be.

The thermostat housing in my 325e was completely blocked by the corrosion. Interestingly it had a ground point there as well. I mention the grounding because of the electrolysis effect of the tap water and a poor engine grounding. Make sure the engine has the same grounds as the e36 offered and they are clean to keep from making the corrosion problem worse. In the case of the eta engine, I am not certain that the ground on by the thermostat housing was making the issue worse, it was just interesting.

https://www.vehicleservicepros.com/collision-repair/on-the-shop-floor/article/21167263/metal-shop-electrolysis-and-grounding-101

[Chilezen]

This looks like the reaction when the incorrect water is used. I bought my 86 325 and the head / thermostat housing was chock full of that stuff. It is aluminum corrosion.

How well grounded is the engine?

That's the answer I got elsewhere. This could be from when I had to add water due to a leaking head gasket. I had to drive the car (no other option) and distilled water wasn't always available... so tap water was used. It wasn't in there long, I did empty it a number of times to diagnose that particular issue, but I guess the damage had already set in.

So now I'm googling the best way to remove aluminum oxide deposits.. which seems to parallel calcium buildup. In this situation, people are saying to use vinegar and baking soda. I'm wondering if that can be safe to using in an engine. More googling...

Why do you ask about the grounding of the engine? I would say it's fine.. I don't know how much better it could be.

[jbontke]

Your car is making meth.

This looks like the reaction when the incorrect water is used. I bought my 86 325 and the head / thermostat housing was chock full of that stuff. It is aluminum corrosion.

I first experienced this by using the wrong water in my Rx7 and it cost me an engine. Slowly the radiator plugged up eventually overheating the car. I could literally feel a cool spot in the radiator where the tubes were clogged. You may want to see if a shop will flush your radiator and verify its not clogged.

How well grounded is the engine?

[Chilezen]

When did you put that blue junk in?

Well, it's a chemical flush, so, I added it about an hour or two before draining it. I added it to help remove the sediment. The flush definitely isn't responsible for causing that.

[moatilliatta]

When did you put that blue junk in?

[moatilliatta]

Additives usually cause headaches. Id assume it was the blue devils if you google what it does to the internal bits. .

[Chilezen]

Fast forward to yesterday, I'm replacing the hose and I'm about to put a new Stewart pump in, that I got replaced under warranty.
I go to drain the coolant again. Awesome.

Side note, I love this drain hose I made.



Thinking of selling them too...

Anyway I'm seeing a lot more of this crap:



I have to use a pick to unclog it, and pour more water in to flush it.
There's a lot more of it this time, probably because I actually put in the effort to unclog it this time.



Here's how it looks sans-water.



WHAT IS THIS AND WHY IS IT HERE??


So I decided to, before replacing the pump, to run a "radiator flush" to help clean out... whatever could be stuck in there.
I used a "Blue Devil's" brand, poured it in with more distilled water, bled the system, drove around, and drained it.
Less crap came out, which is good. I feel like there's more in there still.

Please advise

Any ideas on the cause, and how to prevent it, and why the car still has cooling issues...

[Chilezen]

Wellll I'm back, because why would this car make my life easy.

I still have some unusual temperature fluctuations, which I'm trying not to be concerned about, but I just can't but feel like something is still wrong.

Not too long ago, I noticed a leak coming from somewhere around the water pump area. Coolant was being hurled with the help of the pulleys, so it was hard to trace the source since everything was being covered.

Eventually I concluded the water pump shaft had some play in it, and was the source of the leak. Since I had my original BMW water pump tucked away in a box, I dug it out and replaced the Stewart pump with it.

When I drained the coolant for this job, I found this:



It's very cloudy. What the hell?

I finished the job, put new coolant and distilled water in, and noticed the leak disappear.

About a month later...



The upper radiator hose burst on my way home. On the right side there, next to the oil filter housing. Nothing could have been rubbing it, and it's a "new" hose (less than a year old). Rein brand.
I had to walk a mile each way to go buy a new hose, which didn't even fit correctly (my only option was a Gates brand that was too short, but it BARELY fit. I had no choice at the time, and thankfully, it held!)
I just added more distilled water because I knew I would be replacing the hose again soon.

[Panici]

Glad you finally got it solved.
Hope you get the car back soon!

[Chilezen]

knock on wood that you won't need this, but if you ever do another aluminum block, just run the stock (aluminum block style) headbolts.

The whole headbolt stripping issue seems to be people in NA using the iron block bolts. The euro guys seem to not have any issues (maybe they are just more familiar with the aluminum blocks because they're so common), and even run them to >500whp without issues.

I've never heard of such a thing, that the head bolts are different. I hope somebody in the future finds this out before their own rebuild. A distinction like this should be up front when talking about this engine.

I tried to tell you. I wasted almost 2 years chasing my problem, replacing the same parts...when a simple block test would have revealed the problem. Glad they are making it right and not telling you "it was fine when it left the shop."

Yesssss I hear everyone loud and clear now.. What threw me off was the leak-down test showing good numbers, so I dismissed the gasket/head as a failure. Now I see why the combustion tester would have caught it when the other test couldn't.

[reelizmpro]

I tried to tell you. I wasted almost 2 years chasing my problem, replacing the same parts...when a simple block test would have revealed the problem. Glad they are making it right and not telling you "it was fine when it left the shop."

[jbontke]

3 1/2 weeks later, we have an update from the shop.
I imagine they opened it up and went, "oh, sheet."

As a reminder, this is an aluminum block. So the right thing to do is to Time-cert the block for the head bolts. They did.
But he says he found some of them loose. Somehow they backed out, reducing the clamping force. Hence, combustion could leak into the coolant.
This explains why the engine seemed fine in the beginning, before the head bolts were loose.
I certainly wouldn't have found this out easily. The only way was to take the head off.
He says the head and the block are still straight, so that's good.
To resolve the issue, he'll install new Time-certs the next size up, and put on a new head gasket.

I'm really bummed this happened the way it did. I feel bad for them, finding a problem like this. They're making it right, and I'm happy they're taking care of it.

A combustion leak detector is an easy was to determine of you have a leaky head gasket. I used a harbor freight kit (https://www.harborfreight.com/combus...tor-64814.html) to find the issue on a Cadillac NorthStar engine. The car would run fine under 40mph. But at highway speeds or punching it form 30-70mph, the car would overheat.

[Northern]

Glad there is finally a resolution to this. I wouldn't have any hair left after fighting this issue for almost half a year.