So I had my car walnut bashed (supposedly) in Feb. The car came off the road about a week later because I still had knock/missfire issues.

I left it with a friends workshop and arranged to get a few things addressed like timing chain, clutch and a few other things as well as obviously diagnose the missfire/knock. The engine was removed to make the whole thing easier.

Just before we decided to put the motor back in tonight, we thought we would double check the intake and discovered that it was quite badly coked up again.

Since getting the walnut blast job done, the car would be lucky to have done 300-500kms ~ 300-400 miles.

Could an intake valve really carbon up this much within that amount of KMS. To top it off I added a catch can just after the walnut job, so in theory that **** should be in the catch can (worst case).

Thoughts?

 

I'd like to think they shouldn't be, but with these engines, I'm not so sure. Also, catch cans as a whole do very little for carbon build up. That is unless you have a very intricate catch can set up.

 

Sounds like the job wasn't done and you paid for nothing.

 

The only way to know for sure is to do the walnut shell blasting yourself, then check the intake valves again within the same mileage and see what they look like.

 

What kind of job is it to pull out the valves and clean them yourself?

 

Just use blasting tools to clean the valves as its not a feasable option to remove the valves and clean them.

 

Seems like you need to have a chat with the shop that you paid to do the walnut blasting. Hopefully your invoice has your mileage at the time. Or perhaps you have some other way of proving your mileage close to Feb.

 

you probably got hosed, and they assumed you'd never pull the manifold off to check.

does your engine consume a lot of oil? this would indicate bad valve guides, worn rings etc, in which case that carbon can build up faster than you'd think....but after 3-400 mi, I think that they likely did nothing, or a quick and minimal job.

 

you got ripped off . No way that is 3-4K miles , looks like 30-40K miles

 

How much did you pay for the walnut blasting? I'm guessing all you got was some kind of chemical cleaning (think seafoam).

 

The company that did it are being somewhat reasonable. The owner said he did it himself and has pictures of before and after, but it started getting more sketchy after he said he would take a while to get them as he changed phones since then.

He tells me he had to do both a chemical and walnut clean. I'm of the opinion that he just did the chemical clean because he ran out of walnuts or something. The catch can has no residue in it, and even while the car burns a little oil, it hadn't used any in that space.

Engine has also been compression and leakdown tested and comes up ok, I know they can be misleading with carbon buildup, but there should at least be some abnormalities in the test.

I've sent all the pics to the people that supposedly did it. Hope to get a positive response from them and not a "we did it, go away" response.

 

Actually I don't see carbon build-up on the valves, but they look like there are covered in a thin black residue. There are areas that look like there are lump carbon deposits about the valves.

 

They look similar to the shots circulating around on the net for R56 with carbon problems. Then again, the guy that supposedly did the job said he used chemicals as well, maybe the chemicals have broken it down a little and made it more of a sludgy mess.

This is a shot of another one of the intake ports (pretty bad shot, but it still shows bad buildup).

 

That looks much worse, it doesn't look like walnut media was used, no one had this valves property cleaned. Obviously the chemical cleaner didn't come into contact with the area above the valves do to gravity.

 

Yes, they should be pretty clean with short mileage. Hope you can get the pics.


DIY here and pics of the valves afterwards and before. Some get pretty bad and have over 100,000 miles . The walnut blasting does wonders and the chemical thing is not needed , once you shoot them with the wand and walnut, the carbon comes right off.

https://www.northamericanmotoring.co...-cleaning.html

 

Go and talk to some other mechanics at the shop where you had the valve cleaning done.

Seems like you have to check everything that auto repair shops do, even in Perth, Australia.

 

I spoke with the garage owner again who was quite approachable about it. He wasn't defensive and didn't admit to not doing, but also didn't admit to doing it.

It appears he is going to refund me the money I paid, which I guess is the least he could do.

I'm waiting to hear back from a few workshops to see if they can do it as my existing mechanic doesn't have the setup, he is going to try and clean it by hand, I said that was ok as long as I don't get a big labour bill. If all else fails then I'll order all the walnut kit myself from ECS.

Cheers Everyone!

 

It is best to have before and after pics verifying what was done...simple for the tech to do. We show the owner in person if they are present as soon as the IM is removed and a boroscope is inserted. Only way to prevent this is stopping all the ingestion causing it, and that takes a special separating system to do so. As far as severity and how quickly they coke up, just get anyone with only a few 1,000 miles on theirs to remove their IM and you will see how rapidly they do build up. By 10k miles most loke like heck.

 

How can he not have the equipment!?

Heck, I have the equipment and I'm not a mechanic.

 

Hope your mechanic can get it done for you , glad you got the refund. Maybe he confused your MINI for another MINI he did ?