Corrosion problem 1GM10

[Behome]

Just found that the timing case on my engine is so badly corroded from leakage at the rear of the water pump housing that here is no metal left for the bottom bolt. Any suggestions should of engine out and a massive bill.
I’d not spotted this and it appears to be an inherent fault which has crept up over many years.

 

[HissyFit]

Have you kept on top of replenishing your pencil anodes? Hopefully it will be limited to your timing case, and you'll be able to get one of those second hand, but sod's law will have it that other hidden damage has been caused.

 

[Sniper]

I had the same issue with my 1Gm. Obviously replacing the case is the ‘best’ solution but it’s not an easy job and not cheap either. I used some plastic metal stuff to form a patch which held a thread sufficiently to keep the pump in place. It’s not by any means a great solution but it kept my engine going for a few more years until I replaced it. If your engine isn’t leaking oil it’s worth a try.

 

[Behome]

Thanks Sniper. This was me thought. I was given an estimate of over £1000 for a new cover fitted,plus having to take the engine out. Just not viable for me. What type of plastic metal did you use.
One mans temporary fix is anyone mans sales opportunity. If I can get a few more years out of it I’ll be happy.

 

[Sniper]

Thanks Sniper. This was me thought. I was given an estimate of over £1000 for a new cover fitted,plus having to take the engine out. Just not viable for me. What type of plastic metal did you use.
One mans temporary fix is anyone mans sales opportunity. If I can get a few more years out of it I’ll be happy.

Can’t remember the exact brand but it would be something like this:
Plastic Padding Super Steel Epoxy Weld | Halfords UK

obviously surface preparation is important and I think I used some sort of etching primer on the bare alloy. It was a few years ago so the details are a bit blurry. It certainly held out for at least five years

 

[Gixer]

Mines done the same, although I have just enough thread left if I use a long bolt.
have you tried a longer bolt? I was surprised how deep the thread went.
just a thought.

 

[Tranona]

Have you kept on top of replenishing your pencil anodes? Hopefully it will be limited to your timing case, and you'll be able to get one of those second hand, but sod's law will have it that other hidden damage has been caused.

Nothing to do with the anode - that is for the engine block. The timing case corrodes because water leaks from the pump which is attached to iy, and the steel screws that go through the aluminium casting into the block.

 

[Tranona]

Just found that the timing case on my engine is so badly corroded from leakage at the rear of the water pump housing that here is no metal left for the bottom bolt. Any suggestions should of engine out and a massive bill.
I’d not spotted this and it appears to be an inherent fault which has crept up over many years.

Is this the bottom bolt for the water pump or the one that holds the timing case onto the block? If the former then I guess the only answer is a new timing case. Like others I repaired the corrosion on mine with a metal laden epoxy. Don't know what brand as it came in a yoghurt pot from the tank repair workshops at Bovington. Once sprayed with Yanmar grey you could barely see it.

 

[Oily Rag]

Engineering companies use this stuff: Belzona Industrial Protective Coatings and Composites

Good luck with it.

 

[HissyFit]

Nothing to do with the anode - that is for the engine block. The timing case corrodes because water leaks from the pump which is attached to iy, and the steel screws that go through the aluminium casting into the block.

You are probably right about leaks from the pump, but the pencil anodes are for more than just the block.

The pencil anodes galvanically protect everything that is not electrically isolated from them. The timing case is not isolated from the engine block because steel bolts join the two. Engine blocks are not the most vulnerable item, being thick walled steel castings, but they are a convenient location for a threaded hole to hold the anode in the coolant stream. Heat exchangers tend to be the more vulnerable items, and they don't have any protection other than the pencil anodes in the engine block.

 

[Tranona]

I agree that the anode is often ignored. However the corrosion the OP describes is caused by salt water leaking from the water pump and forming a local galvanic cell between the steel screws that hold the case on and the aluminium of the case. There is no salt water from the cooling system anywhere near the timing case. The case therefore cannot "see" the anode through the water in the water jacket.

The 1GM is indeed a cocktail of mixed metals, particularly around the water pump area with aluminium, mild steel, stainless steel, cast iron and bronze all mixed up. However, if the pump does not leak they all seem to co-exist quite happily. The advice is to watch that area for leaks (which also corrode the oil pipes) and deal with them promptly. Not easy though because of accessibility.

 

[rotrax]

Engineering companies use this stuff: Belzona Industrial Protective Coatings and Composites

Good luck with it.

Forty odd years ago I repaired a Honda 250 twin cylinder head that had crashed and the force had ripped half of the L/H exhaust port fixing out.

Belzona metal fixed it - it kept going for years.

It was a tricky repair though, 1/8th welding rod was used as dowel pins.

The owner, a young lad, had third party only insurance. We gained a customer who supported us for years!

Good 'ole Belzona!

 

[penberth3]

Forty odd years ago I repaired a Honda 250 twin cylinder head that had crashed and the force had ripped half of the L/H exhaust port fixing out.

Belzona metal fixed it - it kept going for years.

It was a tricky repair though, 1/8th welding rod was used as dowel pins.

The owner, a young lad, had third party only insurance. We gained a customer who supported us for years!

Good 'ole Belzona!

+1 for Belzona, it's been around a long time. Like a lot of "industrial" products it wasn't easy to find in small quantities, but now we have google to help!

 

[Behome]

To revive this thread, Thanks to all who responded.
I can confirm that plastic metal plus replacing the seals on the water pump resolved issue for the remainder of the season.

I did have the usual corrosion issue with oil pipes and a massive leak, after replacing with hydraulic pipe (£20 ) I ran the engine to test for oil leaks only to find the water pump leaking water again. I'm assuming this intimates replacing the shaft.

 

[andsarkit]

If you need a new shaft, contact Paul Martin at ffsystems for a new shaft. He can even make them in super duplex stainless which should avoid the crevice corrosion and consequent leaks. ff systems I was quite impressed with the quality of the work he did for me. I think he is also 'Dinghy Man' of this parish.