Turbo Air Inlet Tube Contamination.
 

2008 HHR SS 16 months old/ 9,600 miles.

I removed the air tube that goes from the air cleaner to the turbo inlet to check the turbo. With the tube removed, you can look in and see the turbo compressor and reach in and twirl it to see if there are any irregularities.

I was surprised to find that the air tube was contaminated with a dark thick oil sludge leading down and almost ready to be sucked into the turbo. The PCV valve comes in to this air tube, so the oil is probably a result of that.

I changed oil & filter at 3,000 miles, and the oil life monitor now says 40%. I use regular Mobil-1 oil.

Question : Does anyone with an HHR SS use Mobil-1 Extended Performance ? I wondered if this might have any effect on the air inlet tube oil contamination. I think the Mobil-1 EP is basically the same as regular Mobil-1, but with a more extensive additive package.

As far as i know it just uses regular Mobil 1.

your inlet tube contamination is normal, the engine produces a fine mist of oil that goes into that tube, resulting in oil in your intake, but im suprised to see that you have a sludge buildup, that soulds a little excess with less than 10k on the car.

Mobil 1 EP doesn't meet the same specs as the regular Mobil 1, I think it's the GM 4718 number that we are looking for- for the turbo engine the EP didn't have it on the bottle

I previously owned a VW direct injection turbodiesel with intercooler. At 70,000 miles, this same type of contamination had crudded up the intercooler and the intake manifold.

Can we expect this same process to attack our LNF engines ?

why not just put a catch can on?

How does the catch can work ?

I got to thinking about the sooty exhaust that the HHR SS produces, and I remember that the oil started looking dirty soon after oil change. I am told that the direct injection results in the sooty exhaust (which seems strange to me - with fine metering injectors, precisely controlled, you would expect the opposite). Anyway, this all may be contributing to the PCV system producing more crud than might normally be expected.

I did this to my '95 Eclipse. Just buy a fuel filter and splice in to the breather line that leads out of the engine intake to your intercooler intake pipe, point the fuel filter flow arrow away from the engine. Get a clear one, so you can see when it's time to empty it.

This is a common practice for all tuners of turbo engines. Keeps the intercooler clean of oil.


If you have a lot of miles on, time to clean the intercooler. Remove the intercooler from the vehicle, Use some brake-cleaner and water, heavily clean it.

The easiest/simplest is a water separator used in air systems. Go to Home Depot / Lowes and get one. Used one on my 94 Impala SS & Cadillac STS to stop the same problem. Looks like I will need to do the same thing with the HHR.

Dennis -

Please elaborate. Is this like a sediment bowl like would be used in a compressed air line ?

Here is an expensive version of what some are talking about. http://store.crawfordperformance.com/store/products/334

And a simpler, cheaper one like you describe above that I am going to give a try... http://www.jegs.com/i/JEGS/555/52205/10002/-1

And yet another "overpriced" example http://www.conceptualpolymer.com/new_page_1.htm

I also noticed a small amount of oil in the turbo inlet area (clean oil, no sludge).

That Jegs air filter is way overpriced, along with most of the pretty, machined, anodized "catch cans." It can be duplicated for half the money at Home Depot as a compressed air filter. If you really want to do it right, get a coalescing filter specifically designed for oil mist and vapors. These are available at Mcmaster-Carr.

We LS1 owners have been fighting oil contamination for years. It lowers your octane and builds up thick carbon on the piston tops. I got so tired of it, on my new motor I vent the crankcase to atmosphere with a BMW electric smog pump. Don't tell Al Gore.

Evidently a lot of folks have been updating to the ls6 PCV setup with the separation chamber. https://www.chevyhhr.net/gallery/fil...and_ls1PCV.jpg

The later LS1s had that as well. It helps some, but not enough. Even the LS2 and 3 variants still suck oil. Most of the enthusiasts still have to use some type of catch can or filter.

"If all else fails, read the instructions"

I decided to read the trusty Factory Service Manual. Page 9-1217 has a description of the turbomotor PCV system.

In a normally aspirated motor, there is usually a vacuum in the intake manifold, and the PCV system consists of a connection from the valve cover to the the intake manifold thru the PCV valve.

In a turbocharged motor, there may be pressure in the intake manifold, so a more complicated system is used. There is a primary system similar to a NA motor, and a secondary system that vents the crankcase into the turbo inlet. According to the SM, this system is supposed to handle the problem of contamination of the throttle body and other parts of the induction system, but in practice, it doesn't accomplish this, if my experience is typical, rather than a fault with my system. I don't fully understand how the whole system operates, but it seems to me to be a more complicated thing than just installing a single catch can somewhere in the system.

Further thought and study of this matter appears to be needed.

I wonder how the 2008 HHR SS owners with much higher miles are doing with this problem...

Good suggestion. Reading that also gives a hint that the folks who are having an actual build-up (coking?) may have a bad check valve.

https://www.chevyhhr.net/gallery/files/4/9/0/4/PCV1.jpg
https://www.chevyhhr.net/gallery/files/4/9/0/4/PCV2.jpg

I was following my wife just yesterday and we were playing a little cat and mouse....safely of course. She was in the HHR SS.

I noticed our SS actually smoking when she accelerated hard. Fine black smoke out the exhaust like a modern diesel. Just a hint of it but indeed noticeable. Also my soot level is on the back of the car is pretty bad even only after one week.

How can this be an acceptable practice in this day and age?


http://riverdavesplace.com/gallery/d...p?imageid=1227

Direct injection has more soot than ported injection, but oddly enough, is more fuel efficient.

Safety in AFR for a turbo means being a little on the rich side. How do they get away with it?? Most emission testing isn't going to involve WOT boost conditions so it's never seen.

So after we have had a lot of discussion on possible remedies with examples of engine types that have a problem with oil contamination from the PCV system, and now after some investigation I am ready to say this is a non-problem for a properly operating SS 2.0 Turbo.

My car has had the Hahn tune running up to 24 psi boost for most of its 24,000 miles, and after looking at all the various parts in the intake tract (see photos of turbo inlet pipe, and turbo outlet) I see no evidence of "sludge" or even a light mist of oil (all bone dry). Also checked the old intercooler and pipes pulled off at about 18,000 miles, they are also completely clean and dry.

Conclusion: If you have oil or worse, "sludge" in your inlet tract, something is wrong, get it fixed.

https://www.chevyhhr.net/gallery/fil...oinletpipe.jpg

https://www.chevyhhr.net/gallery/fil...o_outlet_2.jpg

build up
 

When I replaced my spring I noticed a lot of sludge in the bootom of the pipe as well.