Quick Questions

[deedub 91]

21 minutes ago, Vass said:

Some see it as an "upgrade", the logic being lower pressure = less strain on the plastic & rubber components in the cooling system = longer life for the cooling system components.

The counter argument is that lower pressure = lower boiling point = higher chance of vapours in the system. Gases don't transfer heat nearly as efficiently as fluids, leading to localised hot spots or hot pockets in the engine, which obviously isn't good.

This is interesting. Thanks for the explanation.

3 minutes ago, gjm said:

As suggested, stick with original spec if possible.

Yea I'm probably going to do some preventative maintenance on the cooling system while giving it a flush. I'll be ordering the OE cap.

[Neal 565]

1 hour ago, deedub said:

Just noticed that my coolant reservoir cap on my 98 E36 318is has a 1.4 bar cap. Checked real oem and it should be 2.0 bar. Trying to understand if there's a reason PO would intentionally replace with lower pressure cap. May have just been the best option available.

 

Lower pressure could also be a result of the 90s e30 cap recall. There was concerns around pressure build up and scolding an unsuspecting owner.This one was for m20s and I remember being sent a new cap for my 84 323i

 

https://bmwtechinfo.bmwgroup.com/sib_attachments/B170293.pdf and

https://charm.li/BMW/1984/318i (E30) L4-1766cc 1.8L SOHC (M10)/Repair and Diagnosis/Technical Service Bulletins/All Technical Service Bulletins/Recall - Coolant System Overheating/

 

 

 

 

Edited Thursday at 09:05 AM by Neal

[DC3 47]

On 2/21/2025 at 8:01 PM, Twistee said:

Can anyone recommend an electroplater that does Gold Zinc Passivate? I have a pile of nuts, bolts, pipes etc that I would like to have re-plated.

I've used Acme in the past with good results.https://acmeplating.co.nz/

[deedub 91]

On 5/15/2025 at 7:45 PM, deedub said:

Just noticed that my coolant reservoir cap on my 98 E36 318is has a 1.4 bar cap. Checked real oem and it should be 2.0 bar. Trying to understand if there's a reason PO would intentionally replace with lower pressure cap. May have just been the best option available.

Does anyone know if there are benefits to 1.4 over 2.0? Or if it even matters much?

Some context around this after changing the cap and monitoring coolant level over the last few days.

Before posting I noticed the coolant level in the expansion tank was dropping while monitoring it over a week. 1.4 bar cap looked in bad shape and one of the O rings looked to have shifted. After posting this I was able to get my hands on a new Meyle 2.0 bar cap locally. After swapping to the new cap there was an initial drop after the first drive. But coolant has remained at that level and has stabilised since. Did all the usual coolant leak checks with the old 1.4 cap. Nothing. Only thing that stood out was the condition of the cap.

I'll keep monitoring but was wondering if it was an internal leak for a a bit.