Engine won't start after Top Engine Cleaner soak?

[oilyriser]

Out of necessity, I discovered a trick for starting an engine with plugs that just keep getting fouled (loose carbon and oil from piston soak). After an hour of trying things like cleaning the plugs with carb cleaner, and using new plugs, I tried this:

I squeezed the plug gaps WAY down, to about 1/2mm or 0.02 inch, and the engine fired up easily. I let it run for a while to clear out the oil, let it cool, put in the new plugs, and everything was fine after that.

GM should print this on the label of their Top Engine Cleaner.

 

[ChrisW]

Sounds like if you have to put the gap that low, something in the ignition isn't putting out a strong enough spark to jump the regular gap.

 

[oilyriser]

I hope not. The plugs were getting shorted by the balck oily mess in the cylinders. The car runs fine now.

 

[Seth_TJ]

you could also use a "wet plug", I have them to use on my Jet Ski incase I hydro the motor. It aids it getting it running again with the assistance of blowing the water out and a water disperstant.

All it is a plug with the electrode cut (homemade) off so oil, gas, and water can't block the gap where the spark jumps. Supposedly works great, haven't used them yet (knock on wood)

 

[T-Keith]

IMO, GM top engine cleaner is a very old tech and poor choice for modern engines. What car are you trying this on?

-T

 

[oilyriser]

It was recommended by the Saturn dealership.

 

[drifter420]

quote:

---

Originally posted by T-Keith:
IMO, GM top engine cleaner is a very old tech and poor choice for modern engines. What car are you trying this on?

-T

---

Why is it a bad choice for modern engine? I haven't done mine yet.. and getin auto RX or whatever is called is virtually impossible unless I drive to the states.. but I thought top engine cleaner might work better as it goes thru from intake down.. so the valves would be cleaned also.

 

[T-Keith]

A fuel system cleaner like FP or Techron can clean the valves and combustion chamber, what else do you need to clean. I've found the large amounts of harsh chemicals in GMTEC is hard on other components like the plugs, o2 sensors, cat, ect. Often these have to be replaced. They also can thin your oil and possibly cause problems with that. Some cars have problems with it pooling in the intake and not reaching the combustion chamber.

It was designed for carbed engines where the fuel was introduced before the intake manifold. I see no reason why the intake of a modern MPI engine should need cleaning.

I've found FP and a throttle body cleaning much more effective in my high mileage engines.

-T

 

[Gary Allan]

quote:

---

I see no reason why the intake of a modern MPI engine should need cleaning.

---

Well I'm in agreement on your point about the carb air/fuel mixture thing. There is one byproduct of the evolution from carb/tbi to multipoint. Depending on the vent system's point of entry ..all the blow by vapor accumulates in the intake. This naturally gets washed off at the point of fuel injection ..but still allows, over time (and we all typically see much "over time"), a substantial build up. I'm still unsure of the appropriateness or propriety of allowing all of this stuff to migrate enmass into the combustion chamber(s). I imagine that most of it would simply blow through ...but

I imagine that a sensible routine would be in order to limit both the build up and the amount of impact realized by removing it.

 

[T-Keith]

I guess I've never seen that much build up expect around the throttle body. It also seems that a build up in the TB would make a much bigger difference. This can be cleaned with a TB cleaner that is safer and more effective then a "inhaled" product. Like I said I've tried it on my wife's 180k+ mile 3.8 and didn't notice a thing.(Other then a dead O2 and a lot of smoke.

)

 

[SHOZ]

Almost all cars with two intake valves and a dry intake will have this problem. I use a PCV condenser can and it has just about eliminated all carbon depots in the intake system from the TB to the valves.

 

[GMBoy]

T-Kieth,

As for GM Top engine cleaner being old tech - that may be true but GM still specs it for top engine and decarbonizing its NEW engines. There are even bulletins out that specify its use. Plus, today's engines still work the same as the old ones..you know fuel, air and spark....

It's really good stuff but you are right, its harsh so only use it when needed!

 

[pitzel]

Yet another good reason to use a synthetic diesel oil -- the stuff is designed to do a much better job with the blowby gasses than does dino.

I have an early 90s GM 3.1L V6 engine, and before I made the switch from grandpa's pennzoil to synthetic, I decided to give the throttle body a cleaning. What I removed was almost a thick tar-like goo from the throttle body area, as well as the intake plenum.

After putting Mobil 1 in and running for 4k miles, I repeated the same exercise. The goo wiped away very easily with a simple rag, and I didn't even have to break out the mineral spirits to dissolve the crud.

I am convinced that the use of synthetic oil has made my PCV and valve breather gasses much less likely to form deposits in the intake. Which should provide significant benefits over the longer term compared to cheap dino Pennzoil.