Overheating 1985 1.9ltr petrol

[Azzman1000]

Hi all,

So I ran a compression test, engine hadn’t been started for a few days and oil was cold so not sure how accurate it will be. 3 out of 4 were around the 120 mark. Number 1 cylinder however showed 0 compression. Took the head off and the exhaust valve was broken with a massive hole, I’ve pulled the valve and the guide is very sloppy.

Also found a hole corroded between a coolant  port and one of the head stud holes and small but serviceable cracks between valves. TBH I think the heads are gone, but I won’t be able to layout the money for AMC replacements in the next 9-12 months so I am considering replacing the valve (leaving the sloppy guide) and bolting it back together. I really don’t feel like it’s worth having a shop fix the hole and putting new guides in. By the time I outlay $$ for that I may as well spend the bit more on new heads.

I’m interested in everyone’s thoughts ? Am I silly to do so ? Will it hold up for the short term or will exhaust gasses pass through the sloppy guide and cause issue/damage. Coolant passing into the stud hole shouldn’t be a big problem given they run straight into the water jacket anyway ?

[luckyphil]

Hi all,

So I ran a compression test, engine hadn’t been started for a few days and oil was cold so not sure how accurate it will be. 3 out of 4 were around the 120 mark. Number 1 cylinder however showed 0 compression. Took the head off and the exhaust valve was broken with a massive hole, I’ve pulled the valve and the guide is very sloppy.

Also found a hole corroded between a coolant  port and one of the head stud holes and small but serviceable cracks between valves. TBH I think the heads are gone, but I won’t be able to layout the money for AMC replacements in the next 9-12 months so I am considering replacing the valve (leaving the sloppy guide) and bolting it back together. I really don’t feel like it’s worth having a shop fix the hole and putting new guides in. By the time I outlay $$ for that I may as well spend the bit more on new heads.

I’m interested in everyone’s thoughts ? Am I silly to do so ? Will it hold up for the short term or will exhaust gasses pass through the sloppy guide and cause issue/damage. Coolant passing into the stud hole shouldn’t be a big problem given they run straight into the water jacket anyway ?

Perhaps consider advertising for a good used head.  That one is stuffed.

[Azzman1000]

Perhaps consider advertising for a good used head.  That one is stuffed.

Yeah, I figured as much. I guess I better do the right thing ! wish it had held out till next year.

[Azzman1000]

Anyone had experience with AMC heads ? From my quick research they’ve had trouble in the past with the valves and I found GoWesty does modified ones where they install their own valve assembly.

[Syncro27]

Ive now had 3 vans all with AMC heads and all with stock valves that came with the AMC heads....no issues with any of them so far but Ive only had a van with stock engine in it for about 8 years. My current one is up to its 4th year on the road with me - no valve issues.

[gazman]

We use AMC heads at work and they are fine - right out of the box. If there was ever any issues with them they've long since sorted them out...

[grumble]

Ive now had 3 vans all with AMC heads and all with stock valves that came with the AMC heads....no issues with any of them so far but Ive only had a van with stock engine in it for about 8 years. My current one is up to its 4th year on the road with me - no valve issues.

AMC did have a few issues a lot of years ago, I had one 2 litre head with a loose valve guide the head was replaced under warranty by the supplier and I carried part of the labour. I used their heads on any VW's that need them in my workshop with no problems apart from that one.

[Grantus]

I’ve looked for AMC heads on older VW’s for sale, to see if there has been any engine work done on the vehicle, or if it’s the original heads, going to need serious $$$ spent soon.

[Azzman1000]

Thanks everyone,

Next question, and please take into account that I’m just a man in his garage with a few spanners not a workshop doing it for customers. With a young family and heading into Christmas spare money is, let’s say, non existent. I want to do what needs to be done but I can’t afford the “would be nice” things

My wife and I were talking today and have decided to bite the bullet and lash out on an AMC head but is it ok to replace the one side only ? I don’t want to pull the other is it’s not necessary and I can’t afford to buy two heads at once.

The other side was pulled a few years back and was in good condition at the time. It’s had all gaskets replaced and new piston rings installed but it is still using the original valves and guides. 

Thanks.

[Oldman]

Totally understand your situation……been there, weathered the storm and come out the other side relatively unscathed!
Unfortunate reality about components that are installed in pairs is that if one is on the way out/had it, its twin will not be far behind.
These things should always be replaced in pairs in my opinion, otherwise you’ll be doing it all again in the not so distant future
Have you seen this ?
https://kombiclubaustralia.com/showthread.php?tid=328
…..could be an alternative……drop the old one out, bolt the new one in?
Any injection of funds hurts….. but most of the time, short term pain = long term gain….