Vapour blasting woes

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Hi all,

I don’t post up here often other than for work, but I’m hoping I can draw from your collective experience.

I bought a car to fix up, engine blown, no compression.

So I stripped the engine down, then also stripped the head right back. The engine has variable valve timing as well as lift so has vanos solenoid’s on both intake and the exhaust. So it’s quite an involved process.

Anyway once I had done that I took it to a company to vapour blast it for me before I took it to a machine shop to be skimmed and pressure tested etc. took off a few thou and pressure test came back as good.

That took some time to be completed work got busy etc, so it took me some time to get the engine back up and running.

Anyway fast forward it’s all back together, but getting faults on Vanos, I’ve gone through clearing and re-learning adaptations etc, then I’ve looked at replacing the solenoids (again as they had already been changed during the rebuild) however when I’ve removed them, they’re completely clogged up with Silica (from the vapour blasting)

IMG_4873.jpeg


I cleaned them out, put them back in, ran the car back upto temp, still getting the fault.

Removed them again, and they’re full again.

So I’m now in a situation where I’ve spent a lot of time and money (basically replaced all ancillaries, oil pump, timing chain) and the engine is clearly contaminated with silica left over from when it was blasted.

My question is, is this on me? Is there something I should have done post cleaning etc? I wasn’t given any instructions on anything that needed to be done before it was put back into use? Or should I go back to the company that cleaned it? Or am I just screwed?

Any help or advise greatly appreciated
 
Imho it's on the engine builder to ensure it's all as clean as possible before assembly.

Whenever we get a block back from the mahine shop, even if it's been acid dipped or hot tanked, we throw it in the parts washer to ensure there's as little possible risk of any debris at all.

I think you'll have to put this one down to experience and tear it apart again unfortunately.
 
I don't know for sure, but isn't a vapour blasting process supposed to be a cleaning process and should therefore generally give a clean finish? If there is fine mesh in some components maybe you would expect clogging, but shouldn't the rest of the engine be clean?
 
Hi Andy,

Thanks for the reply, it has been cleaned a few times throughout the process - the machine shop did put it through their parts washer.

There wasn’t anything visible during assembly I can only assume it was deep in one of the oil ways that feed the Vanos as those are quite small.

I’m also not sure that the bottom end might also be effected
 
I don't know for sure, but isn't a vapour blasting process supposed to be a cleaning process and should therefore generally give a clean finish? If there is fine mesh in some components maybe you would expect clogging, but shouldn't the rest of the engine be clean?
Hi,

Yeah it is a cleaning process, I mean the head was practically sparkling when I got it back
 
If they are that bad then that stuff is going to be everywhere. You need to strip it down completely and flush everything out. I know it's not ideal but it's better to spend £300 now than get it running only to find that crap has gotten into all of your oil ways, clogged up pickups, created premature wear or even worse end up seizing the engine in a worse case. In any case, you are always going to be wondering if any damage is being done if you don't strip it down again.
 
wouldn't you have expected them to plug some of the oil pathways
... slightly different but I investigated getting a bicycle frame vapour blasted and painted / Sussex and believe they protected internal/external threads.

have you maybe called other companies to see what precautions they might have taken to use in any discussion with your one.
 
Just got to chalk it up to experience. Just going to have to strip it all down and do it again.

Is the bottom end okay as I presume the whole lot is contaminated now?

Have you taken the sump off and checked the strainer?
 
Last edited:
What andy_mk3 said.

Cutting the oil filter open should give you an indication of how much crap there is floating about in there.
Sadly it’ll have to come apart again :(
 
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