Rough idle when cold, stall
This car has 40,000 miles. Customer complains of a stall when it is cold, possibly at first braking event. I drove it home last night. After starting this morning it seemed to idle rough, and stalled at the end of my driveway. From then on it ran fine. I believe this is exactly what the customer is complaining of. I'm thinking the problem is being caused by excessive carbon on the intake valves. There is a PIP message ( PIP5029F) for this concern which involves using top engine cleaner. I'm wondering if anyone has had success using this method or if pulling the intake and blasting with walnut hulls is the way to go. I'm aware of Bernie Thompson's machine, but I do not have one, nor do I know anyone who does. Just looking for suggestions.
Lamont, In my opinion there is no substitute for walnut shell blasting. It would be my number one choice. When done there would be no question on the Carbon being the problem. It seems reasonable that it would cause problems. Top engine cleaner is a proven method for years however once baked on a single treatment of anything will not take all the Carbon off. It is on there like cement. If…
I have BG products. They work very slowly. The top end cleaner is the strongest I’ve used. Last job I did took much time and treatments to work. I’ve just started setting up for walnut blasting. Ive got a 20 gallon pot. I’ve learned to use the fine. Next I’m trying to purchase the manifold attachment so I don’t make a mess. Has anyone got recommendations on where to get a set? I got my blaster…
for the hose attachment to the cylinder head…bmw uses at RADIATOR HOSE?!! (with a small hole in it for the walnut nozzle) that fits the vacuum hose for sucking up the walnut shells….also you need to make sure the walnut shells are DRY!!! put them in an low temperature oven for an hour or so… and you must have DRY AIR going into the blaster unit…any moisture and you are constantly taking the…
The BMW machine uses cast aluminum adaptors that are BMW specific. They look like the ones Ronald posted. They can be adapted easily to other ports using by making seals from intake gaskets, solid paperboard or even hose. The shop I worked at used adapted BMW ones for VAG products frequently.
To keep from making a mess, find a radiator hose that fits tightly into the intake port of the cylinder head. Cut a small hole in the hose just outside of the chamber to fit your blaster wand through. Then, hook your shop vacuum to the other end of the radiator hose. This should keep the shell bits from flying everywhere. I keep several different hoses for different sized chambers.
Micheal is spot on! The is NO substitute for walnut blasting. It allows an inspection of the valves and ports as well as the intake system. I have never seen photographic evidence of chemical's coming even close to walnut cleaning.
I've had several VAG cars, where walnut blasting did not make much of a dent in the carbon. Required mechanical scraping, chemical softening, and then blasting…
If that doesn't take care of the problem I would next check trans torque converter lockup stuck on somehow, it it reminds me of a man trans and forgetting to push clutch pedal in, I used work in a construction co garage and we had gm tis2web and I liked it,
I would first bore scope the back side of the valves and verify their condition as to carbon build up.
We removed the plenum and on this engine the carbon buildup was easy to see. We blasted the intake ports with walnut hulls. I have included before and after pictures. However the original concern is still there. At startup, the engine revs to about 1200 RPM which I consider about normal, but it seems to run a little rough. Not a misfire, more of a vibration. I think the substrate is loose in the…
This is my setup for Walnut hull blasting. I took an extra elbow for my Shop Vac and attached a short length of radiator hose to it with Gorilla Tape. I punched a hole in the hose for my nozzle to fit through. The hole is large enough that it allows me move the nozzle at different angles while cleaning. You can easily seal the hose against the cylinder head. I get no media flying around outside…
The 0-9 percent alcohol content I would not be worried about. I have had Malibus of that era with identical symptoms. The issue was when the car went into closed loop the rear 02 sensor was not hot yet and still stuck rich. The ECM would pull all the fuel away trying to get the stuck 02 down. Took about 30 seconds or so for it too wake up. Then it was fine after that. No codes either. Just an…
Was the fix to replace that O2 sensor? I’ll check this out today.
Also not trying to create a mountain out of a mole hill but need to say this. We had 3.6s from mid say 2007 all the way till 2018 or newer (when I was still at GM dealer) that would just seize up for no apparent reason. Didn't matter if they had 10k or 120k miles. Consistent oil changes or not. Bearings would seize up and valves would drop. There was no rhyme or reason. The VVT solenoids would…
After walnut shell blasting the intake valves, and cleaning the throttle body, The car ran normally after a cold startup and no longer stalled. I was a little concerned about the alcohol content reading on my scan tool, but I was assured by a few responses that this was not a problem. Thanks to everyone for your help!