In the last service visit to the dealer they said there is carbon buildup in the turbo intercooler, and will need to be cleaned. Cost $400. They said it will impact turbo performance.
So far I have no problems, the car drives fine.
Has anyone had any issues with that? I could not find anything in the forum.
I know the dealer typically pushes expensive, unnecessary repairs to make more revenues. I'm trying to educate myself on the intercooler subject.

 

Inside the intercooler? interesting - that would be like cleaning inside the engine coolant radiator. So just how does the dealer propose to clean inside the turbo intercooler? Please tell us. And how did the dealer look inside the intercooler? which connector was removed? questions you may wish to ask the dealer yourself.

And how can we even guess at a response, without some data from you: year, miles, type of driving, etc. The dealer has seen your vehicle - we cannot see your vehicle, nor guess at your problems.

 

Nothing flows through the inside of the intercooler except clean, filtered, pressurized air.* Unless there are leaks or breaks in the system piping, it should be very clean. If there are leaks, it should be throwing fault codes.

The outside fins of the intercooler get very dirty, but can be cleaned with a vacuum and combed straight with an inexpensive tool.

The stealership must be trying to pay for a new boat.



* (The pollution-control vapors enter downstream in the intake manifold.)

 

Here's a photo of the turbo. There's some debris on the fins, and some carbon onto the dip stick.
2007 RDX base, 90K, all drive in city.
As I said, the car drives and accelerates fine. I'll ask more as to how they plan to clean the intercooler. Usually you don't get a good answer from the service advisor, he just reads the recommendation....

 

Quote:

Originally Posted by XLR8R

... * (The pollution-control vapors enter downstream in the intake manifold.)

No, you are thinking of the PCV venting into the intake manifold, after both the intercooler and the throttle body.

Quote:

Originally Posted by XLR8R

Nothing flows through the inside of the intercooler except clean, filtered, pressurized air.* ...

But the valve cover vents directly into the turbo air-intake, which means that any oil vapor from the top-end of the engine is pushed through the intercooler, by the turbo. This is bad for both the turbo and the intercooler and the throttle body.

If the correct oil is not used, with a high NOAC vaporization level, that lead to (old worn) oil evaporation (vaporization), which can cause oil vapor to pass through the intercooler. That should not cause carbon in the intercooler, because I don’t think there is high enough heat. But that can cause oil-vapor to deposit on the inside of the intercooler. And since the intercooler is air-to-air cooling, that would decrease the turbo efficiency.

Oil vapor inside the turbo might cause some carbon, although typically the problem is coking of the oil in the turbo-bearings, not inside the air passages of the turbo.

Quote:

Originally Posted by XLR8R

... The outside fins of the intercooler get very dirty, but can be cleaned with a vacuum and combed straight with an inexpensive tool. ...

Take care with the type of cleaner – no solvents, which can be bad for aluminum. I use aircraft type Simple Green, from the auto-parts store, which specifically states that it is safe for aluminum. Probably a good dish soap would also work, such as diluted DAWN brand, which I have used.
---eof

 

Quote:

Originally Posted by stathis

... 2007 RDX base, 90K, all drive in city.

You might consider the occasional *blast* on a freeway onramp, up to redline, but only after the engine is completely warm, after say 30-minutes of normal driving.

Quote:

Originally Posted by stathis

... Usually you don't get a good answer from the service advisor, he just reads the recommendation....

Which is why I have introduced myself to the service manager, and when there is something that I don’t understand, I ask him. And if I still don’t think he has given me a technical response, I ask if maybe he could have a mechanic explain it. But typically, the service manager knows more than the mechanic, technically, not necessarily how to perform the actual repair.

 

The engine oil dip-stick? the only other dip-stick is for the transmission.

That seems really unlikely - have you actually seen this yourself? carbon would be filtered out by the oil filter. And carbon in the engine oil has nothing to do with the turbo intercooler, since the intercooler only passes air, except as noted above.

Do you mean sludge on the engine dip-stick? sludge would be a problem, and should be addressed, or it will clogg the VTEC screen, and the variable cam feature will stop working.

 

Yes, that's that black grime visible on the dipstick. I have wiped it clean it before, and it got all black again.

 

Which oil are you using, and when do you change it?

 

WAIT - do you mean the DIRT on the dip-stick HOLDER, and not the dip-stick itself, as in the picture you have posted? So, not carbon in the engine oil, but DIRT on the dip-stick holder? That is just dirt.

And so, is this post simply about CLEANING THE OUTSIDE OF THE TURBO INTERCOOLER, NOT THE INSIDE? You are talking about cleaning DIRT on the outside of the intercooler - there is no CARBON on the outside of the intercooler. Where would CARBON come from?

I pass.

 

I don't know what the dealer meant by "cleaning a dirty intercooler for carbon buildup".
These are the photos of the turbo, the only thing visible is some debris on it.
I guess I could open the plastic cover held by the four large screws and then clean the fins with a vacuum cleaner with the brush attachment.

 

Yes: the PCV venting into the intake manifold IS pollution control. Having previously been vented to atmosphere, the PCV was the 1st pollution control system; widely introduced in 1961.

The valve cover is not meant to vent into the turbo air inlet. The flow is the other way. The purpose of the valve cover breather hose is to allow clean, filtered air from the turbo air inlet into the engine. It then collects blow-by gasses and exits through the PCV into the intake manifold.

In proper operation, with the correct oil level, crankcase vapors should not backflow though the breather hose into the turbo inlet. If that is happening, there are other problems.

It may be possible that backflow occurs under high boost, when the PCV is closed. However, I have checked my breather hose and turbo inlet recently at 100k miles and not found any significant oil vapor backflow.

 

It means he wants your help to pay for his new boat.

Yes, that is easy to do. Be careful not to bend the fins when you are vacuuming. You can get a fin comb at any auto parts store.

Keep in mind that the underhood airscoop directs road dirt onto the intercooler and top of the engine. It's just external grime that needs cleaned occasionally.

 

Yes, that is precisely what I said, or meant to say in any case. Its reassuring that you found no significant oil in the valve cover breather hose, but aftermarket catch can hookups for turbos are used for a reason.

If heavy boost is often used, and non-HTO-06 spec oil, with a high NOACK is also used, there *may* be some backflow through the turbo, simply because there will be a lot of oil-vapors inside the engine.

The OP did not specify which oil they are using, but Mobil-1 has a fairly low NOACK, but certainly not the lowest available.
---eof

 

I've had all oil changes at the dealer (with the coupons it is a decent deal).
This discussion has been very useful for me.
I'll clean up the fins with the vacuum and see what they say at the next service.
Thanks list!

 

I am not sure how much attenuation to air flow it would cause or how much it would hurt the cooling of the turbo, but is there any reason why we can't put a cheap fiberglass filter (not the pleated kind but the inexpensive type used for furnaces), either on top of the intercooler or in the plastic housing that directs air to the intercooler? Of course, you would need to keep an eye on it periodically. Other than airflow, I would rather the fiberglass catch the bugs than my fins. At 50K miles, about 1/6 of my fins are glogged and no amount of sane vacuuming, or combing, or picking will unclog them without removing the intercooler. Any suggestions?

 

My turbo vents were also clogged up with debris and bugs, and several folds were bent. However, it didn't visibly affect performance. So I use a toothpick to remove stuck bugs and such, and then used the vacuum with the brush to remove the dust and grime. It looks better now. No further recommendations from the service guys for turbo cooler cleanup. Performance still the same, cleanup did not improve anything.

 

If you can remove it, try hitting it from the other side with moderate hose pressure. Don't want too much as you'll risk bending the fins, but it should push the majority of that garbage out. Then let it dry overnight and bolt it back on.

If you don't want to do it now, save it for when your spark plugs are due as you'll have to remove it anyway at that time and you can kill two birds with one stone.

 

Turbo vents, carbon buildup in the turbo intercooler, oh my.

Terminology help for the new guys, but sounds like maybe you got it already?

The turbo, behind the engine, covered by a silver metal heat shield, makes boost.

The top mount intercooler, on top of the engine, enclosed by a black plastic shroud, cools the air that comes out of the turbo and pushes it thru the intake manifold in front of the engine. The IC fins are super thin and bend easily. When cleaning them avoid creating restricted flow from bent fins.

It's easy to monitor both ambient and after intercooler (intake) temps.
But with or without a clean intercoolr, intake temps soar when vech speed reduces air flow across the IC.


I have thought about an intercooler prefilter too. Sounds like no one here has tried it yet. Wonder what the DP would be? And I wonder if it would catch the grains of sand I find stuck between the fins?

 

Since only the top 1/3 of the IC really catches the bulk of the sand and bugs, I'm thinking of just placing a piece of fiberglass filter material over that section of the IC and under the plastic cover. This is the type of filter that they tell you to not use for your forced hot air furnace because it doesn't catch the very fine particles of dust (which I can care less about) but are used by many because they do not limit airflow that can overheat the furnace. Many of my fins are clogged and I plan on using a dental tool to clean them first(toothpick only pushed them in further). My 2012 RDX is already 3 years old and almost 50K miles. I guess in another 3 years and 50K, I'll end up cleaning the whole IC with new plugs and perhaps I shouldn't worry about sand and bugs, but what if I am not the one that changes the plugs. I'm sure a mechanic won't clean it for me. Also, a partially clogged IC doesn't damage the turbo; it will just allow hotter air into the engine which decreases performance....but how much will I really notice?

 

Wait HOLD ON a minute.. the dealer wants to charge you $400 (AMERICAN?) Dollars for what?? "carbon buildup in the turbo intercooler,"

Never to back to that dealer ever again.
At most you may get some oil in the intercooler due to pcv, blowby whatever, its 100% normal for all turbocharged engines to have some of this.

As far as the OUTside of the intercooler? and putting filters and stuff over it?
Just pop it off and wash it out with a hose or if you like perhaps some simple green, etc the cleaner of your choice that will not harm aluminim. There are only a few screws holding it on, its made to come off and on for service. Covering the intercooler in anyway will introduce more heat soak and less air getting to it and causing performance loss, knock, etc.