[Russbmw]

So, had the intake walnut blasted today.

I'll do a proper write up another time, but to summarise what is already probably common knowledge on here, but incase anyone new is reading this - many direct injected engines suffer from the intake tracts getting coked up. Some engines more than others. Mini's are pretty renowned for it, as it seems are the N54 engined BMWs. Lean running (hence more efficient) engines are very sensitive to air flow, so when the intake and valves get gummed up the flow in is not only restricted but also turbulent - leading to slight trembling at idle, dulled throttle response, less smooth power delivery, etc,etc.

A lot of engine stripping just to get to it.



All 6 intake ports looked like this:





After blasting with crushed walnut shells





They ended up looking like this (the white tape at the top of each port was to minimise risk of the breather port getting dust in it):





End result is that the car now idles so smoothly you'd probably not even get ripples if you stood a glass of water on it. Power delivery is much smoother (even though it never really felt *that* bad initially) - now it feels like a new car. Throttle response is immediate, and the odd very minor hesitation I'd sometimes get at about 3000rpm (usually on the motorway in 5th or 6th) seems to have gone as well - I need to check that out further tomorrow.

Work was carried out by Will at TWG Automotive in Camberley (who specialise in BMW and Mini only), for the very reasonable price of £280 - given that it's a good 4 hours work. Him and his other work mate are both ex-BMW techs from Synters, and I have to say, their attention to detail, care, and knowledge are superb.

[RajB]

Another good story. I'll consider getting mine done at some point but probably once I've got a meth kit sorted (as I've heard meth kits are good to help stop the build up).

I've seen a couple of cars with a few thousand miles on them after getting this done and they've already started to build up quite a bit again.

[Phil325i]

Thanks for the useful post. Thinking about having this done, but mine's a N53. Did Will give any indication that he'd found the same issue with naturally aspirated engines? Old Grey Steve posted some pics a while back, but they seemed inconclusive...

[old grey steve]

Originally Posted by Phil325i

Thanks for the useful post. Thinking about having this done, but mine's a N53. Did Will give any indication that he'd found the same issue with naturally aspirated engines? Old Grey Steve posted some pics a while back, but they seemed inconclusive...

You're right I did the 325i(and we've seen 2)wasn't nearly as bad as the shed loads of 335i's we've seen the residue on the valves was more gloopy and wet that the 335i's but they all scrubbed up OK, both drivers report better driving behaviour one reported better fuel economy one said nothing had really changed. Overall is it worth it on these to a point yes but the differences aren't as marked as the 335i's

[AzRiz]

That looks so worth it, I will be getting it done at some point this year hopefully.

£280? I thought it would be more like £350! Looking forward to getting it done, thanks for posting your thoughts and pics mate

[old grey steve]

Originally Posted by AzRiz

That looks so worth it, I will be getting it done at some point this year hopefully.

£280? I thought it would be more like £350! Looking forward to getting it done, thanks for posting your thoughts and pics mate

Its a damn good price for the work required, but I noticed on the first picture (inlet manifold off) that in the background the fuel rail is still in place, which would cut down the time(also means unlike us they've chosen not to move injectors)

[AzRiz]

Originally Posted by old grey steve

Its a damn good price for the work required, but I noticed on the first picture (inlet manifold off) that in the background the fuel rail is still in place, which would cut down the time(also means unlike us they've chosen not to move injectors)

Ahh ok, thanks for pointing that out Steve, it's most likely yourself that I'm going to come get it done by so I will remember to budget for a slightly higher figure

[Phil325i]

Originally Posted by old grey steve

(also means unlike us they've chosen not to move injectors)

Why would you Steve? The injectors won't be affected by the blasting as the valves are closed when you do it...

[dy63]

how quick do you think it takes before they get that black and stuff inside again? considering average mileage of 12k per year?

[old grey steve]

Originally Posted by Phil325i

Why would you Steve? The injectors won't be affected by the blasting as the valves are closed when you do it...

In theory your spot on both chambers are separate but when you blast these shells at such a high rate any stray debris no matter how small could venture somewhere where you wouldn't like it to go and it doesn't take an awful lot say for this to happen if so and the needles on the injectors are so fine then you could have an issue, therefore we chose to remove and plugs the injectors (for safety as well to inspect)also by doing this we can check for oil contamination in the injector chambers(remember 335i's have issues re cracking rocker covers with the injectors removed you can see everything 100% without obstruction)so we chose to remove injector's for a pure preventative measure and again it allows us to inspect the rocker cover and all chambers at the same time as the cracks in the covers seem to start deep down and work there way up(as mine did) and at the same time as misfires on these cars happens for a number of many reasons if you see something like a crack with oil leaking down then you know that a misfire if present could be down to this, but your right Phil they are 2 separate chambers.

Re debris, if you look at the picture below



they look remarkably clean(shows this all works)but look at the valve where it meets the head you'll see shells are still present(and this happens to us and we spend a little time after completing all cylinders going back again and hovering each port out again) all around the visible circumference of the valve in the picture and that's the reason apart from checking things like the cover we chose to remove injectors, plugs of course are removed without inspection.

On the subject of misfires we also carry out pre work diagnosis and smooth running check as well as post work to verify all the above if you follow me.

[RajB]

That's intereting to know Steve that yourselves go a little further with this. Out of interest what would be the charge from yourselves (if you don't mind me asking on here)?

[old grey steve]

Originally Posted by RajB

That's intereting to know Steve that yourselves go a little further with this. Out of interest what would be the charge from yourselves (if you don't mind me asking on here)?

We just chose to set the stall out this way Raj, simple as other places do what they do that's it there is nothing wrong with say leaving the injectors in situ(as pointed out by Phil-quite rightly)but when say you have a misfire you carry out the blasting re assemble only to find you have a misfire that turns out to say be a cracked rocker cover deep in the injector well then the customer might be a bit miffed, we used personal experience on my car to set the stall out re what we do, we won't deviate from that, the actual job done though is 100% representative of the work done by TWG, that I can assure everyone and the results speak for themselves i.e.

Re cost... can't divulge on here due to the old forum rules

[djgandy]

Originally Posted by old grey steve

Re cost... can't divulge on here due to the old forum rules

How many bananas does a bag of walnuts cost?

[Phil325i]

Great explanation Steve. Most thorough as always...

[old grey steve]

Originally Posted by djgandy

How many bananas does a bag of walnuts cost?

Bag of walnuts less than £22 from BMW plus VAT of course, cost of all the time and effort to get this job done £+VAT

[Russbmw]

I'll have a chat with Will, as he was quite happy to explain everything he was doing in great detail, but here's what I understood from him the other day.

2 cylinder intake valves are open, whilst the other 4 are sealed closed. Hence the tissue is there more as a reminder of which ones not to do! Becuase yes, if they were left open, it would cause a big problem! The injectors are not in danger of being blasted with the valves closed, obviously. The small amount of shells left in the valve after cleaning do not harm anything as the combust instantly.

I recall him saying something about the injectors needing removing on diesels, which makes it a more time consuming job.

[old grey steve]

Originally Posted by Russbmw

I'll have a chat with Will, as he was quite happy to explain everything he was doing in great detail, but here's what I understood from him the other day.

2 cylinder intake valves are open, whilst the other 4 are sealed closed. Hence the tissue is there more as a reminder of which ones not to do! Becuase yes, if they were left open, it would cause a big problem! The injectors are not in danger of being blasted with the valves closed, obviously. The small amount of shells left in the valve after cleaning do not harm anything as the combust instantly.

I recall him saying something about the injectors needing removing on diesels, which makes it a more time consuming job.

100% correct Russ what Will has told you, the injectors come out when we do it as stated elsewhere purly for precautionary reasons and nothing more and also(out of knowledge and many dealings with these cars including mine) on the issue of misfires that may owners report we really feel now that we know where their weakspots are its only right to look at everything, not just carry out a procedure that could help but not necessarily solve the customers particualr issue, we'll chose to look at everything.

To the left of the picture below you'll see where the injector is situated and its tight to view everything(also notice the black plastic rocker cover is a little wet).



Look again below when the injector is partially removed partially you can see the crack in the back ground



and this is why we chose to follow our own line on these, we want to see everything.

See the picture below,



This is where my car had a misfire so we ran mine up for a good long while to check as we knew oil was visible in a couple of the plug wells but also via pre work diagnostic suspected an injector issue but wanted to be explore the obvious as well as the unknown, so as I had the issue once the cars been running for 1/2 hour or so we ran my car up and came back to see the oil seeping out the expanding rocker cover crack dripping down the injector wells and thus creating a misfire

Its more time consuming doing it this way and diverts you off the track a bit re doing the blasting but for us its done for the very reason highlighted, a misfire on these can if you don't do a diagnostic pre work(includes smooth running) and a visual check over pose a problem, is it plugs, injectors, colis???

Who knows of the 25+ 335i's we've done including mine seen 3 cars with cracked rocker covers that crack right at the base it would seem and work there way up(oddly enough all including mine-which is pictured on cylinder 3) So everythings out and inspected

[RajB]

Originally Posted by old grey steve

We just chose to set the stall out this way Raj, simple as other places do what they do that's it there is nothing wrong with say leaving the injectors in situ(as pointed out by Phil-quite rightly)but when say you have a misfire you carry out the blasting re assemble only to find you have a misfire that turns out to say be a cracked rocker cover deep in the injector well then the customer might be a bit miffed, we used personal experience on my car to set the stall out re what we do, we won't deviate from that, the actual job done though is 100% representative of the work done by TWG, that I can assure everyone and the results speak for themselves i.e.

Re cost... can't divulge on here due to the old forum rules

Cool and thanks for the further explanation. Understand about costs. Will find out soon enough.

[old grey steve]

Originally Posted by RajB

Cool and thanks for the further explanation. Understand about costs. Will find out soon enough.

No worires also something else we do is re set engine adaptations post the work as well(part of our diagnostic procedure)which enables resets everything engine wise back to zero(won't thankfully effect say an inbuilt re map-which my cars has)but as the cars adapted itself to living with clogged up valves seems right to re set everything and allow the engine to adapt to a nice clean inelt, but it all takes time.

But Russ's valves and ports look great, its a great service we garages a can offer customers and 335i owners can at least know this procedure works as illistrated by Russ's OP

[Russbmw]

That's interesting Steve (as always mate!). I see what you were getting at the other week when we were talking about my car. Before the cleaning, I had managed to get the car to perform it's "hesitation" a few times, and I think in hindsight use of the word "misfire" in my case might have a been a little misleading, as it was not as defined a feeling as a misfire, it was more of a very slight hesitation/stumble.

We did have a good look around - noticed my injectors are quite old ones, so haven't been replaced yet (they're revision 08, whereas I gather they're currently on revision 11). Didn't see anything else untoward thankfully.

My car didn't have any fault codes stored before, or after (thankfully!) - and the adaptations were also reset as required after the cleaning.

Anyway, I wasn't intending this thread to turn into who does a better job, as in my opinion, it's always good to know of decent garages/mechanics across the country - particularly if they can offer the walnut blasting as well (and conveniently for me, TWG are only about 20 mins away!).

They honestly seem like genuinely nice guys, so thought I'd share it.

[old grey steve]

Originally Posted by Russbmw

That's interesting Steve (as always mate!). I see what you were getting at the other week when we were talking about my car. Before the cleaning, I had managed to get the car to perform it's "hesitation" a few times, and I think in hindsight use of the word "misfire" in my case might have a been a little misleading, as it was not as defined a feeling as a misfire, it was more of a very slight hesitation/stumble.

We did have a good look around - noticed my injectors are quite old ones, so haven't been replaced yet (they're revision 08, whereas I gather they're currently on revision 11). Didn't see anything else untoward thankfully.

My car didn't have any fault codes stored before, or after (thankfully!) - and the adaptations were also reset as required after the cleaning.

Anyway, I wasn't intending this thread to turn into who does a better job, as in my opinion, it's always good to know of decent garages/mechanics across the country - particularly if they can offer the walnut blasting as well (and conveniently for me, TWG are only about 20 mins away!).

They honestly seem like genuinely nice guys, so thought I'd share it.

Russ judging by the end result I think they've done a damn fine job as it takes a bit of patience to do the job(and your back hurts with all that bending over)they look spot on and judging by the result if I lived near you I'd visit TWG as the result is superb.

Threads like this are informative hence I like them but garages and people who work in them do things slightly differently based on many things, we carryout the procedure our way now as we feel it's the right thing to do that's all

[Russbmw]

Yeah, lots of manual cleaning to compliment the blasting as well. The backs of his legs must have been killing, as mine were aching jsut leaning in to take photos! LMAO!

If you were nearer mate, I'd have been there in a flash, trust me!

Next time I'm out your way on a work site visit, Ill be sure to call in and say hello though!