Pontiac Solstice Forum banner

Overheating, Knock, Observations, and Questions...Please Comment :)

2K views 6 replies 6 participants last post by  TomatoSoup 
#1 ·
I would like to preface this thread with the information that my car is mechanically stock except for the Trifecta Budget tune. The tune is setup to be turned on and off and other then the ping being worse with it activated it has no effect on the issues I'm having. In fact both of these issues existed before I loaded the tune.

Overheating Story:
So there I was, Driving home from my girlfriends house this fine Christmas morning. It was a crisp 34 degrees outside and I had the cruise set at 70 mph. Not once did I drive the car in an aggressive manner and my speed never dropped below 60 for the entire 10 mile drive. The engine temperature climbed to and hovered between 205 and 212 degrees the whole time. This was not the first time its gotten hot as its been regularly staying between 210 to 220 degrees during city driving with outdoor temps in the upper 50's. These temps have been my norm since just before Thanksgiving when, I had my oil changed at a local quick lube joint, which leads me to my first question. If they had opened the plastic coolant reservoir while the engine was at or near operating temp, would this have caused the system to take in air and develop an air pocket(s)? I have read where air in the coolant system can cause this exact problem and since it started on my thanksgiving road trip, immediately following my visit to this shop it lead me to this conclusion. I have since gone back to the quick lube place in question and they assured me that they check and service these types of cooling systems all the time and have never had this problem develop. They said they couldn't see how air would have gotten into the system from merely opening that overflow reservoir.

My knock story:
My knock story begins somewhere in early july when I found the procedure for the waste gate rod mod. I did the mod, drove the car for about an hour, made a few full throttle pulls, and then adjusted it back to stock after reading that the computer would probably adjust it out anyway. Now I'm still not sure that's exactly when the pinging started but, I read somewhere on here where someone was able to attribute that to their ping/knock issue. Although I am fuzzy on the exact date when my issue started it seems like it was right around the time I did that mod. I can't be sure that was what caused it as I have read and found other potential issues.

Now just to clarify the only time it pings/knocks is under what seems to be high load, abrupt (not no lift) shifts to third and fourth gears. The rpms have been as low as 3500 and as high as the redline when it occurs. Of course the higher the rpm the worse it seems to be. If I granny shift, pause very very briefly to let the rpm drop a bit between shifts and then release the clutch and get back hard in it, it doesn't happen.

One problem I recently found is that the plastic nipple in the turbo air inlet pipe that normally snaps off, had snapped off and the inline one way valve was stuck. I have no idea how long its been broke as I can count on one hand how many times Ive had the hood up since Ive owned her. When I saw that I thought, there's my problem, unmetered air getting into the system causing a lean condition. After fixing it the problem did seem to be less severe but, when I had the inlet pipe off I had noticed that their was a little puddle of oil that had pooled on the inlet of the turbo itself.

This leads me to the next piece of the puzzle. I had read somewhere that with more boost comes more blow by and that oil puddling like I'm having is normal with the high boost pressures you experience with a tuned car. Well before I removed the inlet pipe to fix the nipple I had been seeing boost pressures in the 20 to 23 lb range with the Trifecta tune so, I'm assuming I don't have anything out of the ordinary goin on. The car runs fine and doesn't blow any excess smoke or seem to use a lot of oil. I guess the question here is...Has anyone had the same or similar problem with the oil pooling and did it contribute to or was it the cause of their ping/knock problem? Did the ping/knock problem clear up when you addressed the issue? How did you fix the oil issue? I've been considering a catch can.

I know this is a long post but, if you've made it this far thank you and thanx for any input you can give.
 
See less See more
#2 ·
205 to 210 is normal. When the heater is on, the temp goes up 2 - 5 degrees

240 is high. 250 is the danger zone. They are designed to run at or above 200 .

The symptoms of an air bubble in the coolant are having intermittent no heat from the cabin heater and tee rapture fluctuations between normal and normal plus 20 degrees if your temp is less than 220 and consistent, no large fluctuations, then you probably do not have an air bubble
 
#3 ·
My car use to consistently sit around 98-99*C or about 208-210* F ish. I flushed out my Dexcool for a fresh batch with a new thermostat, and the check valves which help to prevent air in the cooling system all at once. When I was done and since then, the coolant temps are now consistently 88-90*C or about 190-195*F.

Secondly, that oil build up you're getting is due to the increased cylinder pressure or boost. The line that runs from the intake off the plastic nipple that is broken, is an inlet for fresh air. It goes through a 1-way check valve that attempts to keep oil from coming out of the line, while letting air into the heads.

It's the second line running from the heads to the turbo that is causing the oil in the intake tube problem. The only way to effectively deal with this problem is to either go back to stock boost, which really isn't an option now is it ;) or to run the line that goes from the head to a breather tank, or catch can, instead of back to the turbo/intake. That way the oil will be collected in the tank/can, instead of going back into the engine.

If you're already seeing oil build up in the intake area, I'd also bet you have oil in the intercooler area. I'd be sure to clean this all out to prevent detonation under high load/boost situations.
 
#4 ·
Mine has always sat around 192*-205*. It rarely goes higher than 205*, unless sitting still with the AC off.

If you have access to a Snap On flexible camera, try to use it to scope the valves/intake manifold. If you've got oil getting that far in the intake tract, that could definitely explain your issues.
 
#5 ·
I have since gone back to the quick lube place in question and they assured me that they check and service these types of cooling systems all the time and have never had this problem develop. They said they couldn't see how air would have gotten into the system from merely opening that overflow reservoir.
The bolded statement above, is wrong. This is the standard response you will get from any "quick lube" station on this matter. Our cars are VERY prone to sucking air into the coolant system if you open the tank when the engine is warm.

Rob is correct about the temperature readings in general.

However, if you now notice the coolant temperature will rise while sitting at a stoplight and it did not before: Then you probably now have some air in the system. If a large enough air bubble gets into the system, then the heater will start to malfunction as Rob stated. DDM has a video posted on the forum on how to remove the air yourself. I also have videos posted with another method to remove the air. And of course, you can also order and install the check valves to help prevent the problem from reoccurring.

My knock story:

One problem I recently found is that the plastic nipple in the turbo air inlet pipe that normally snaps off, had snapped off and the inline one way valve was stuck. I have no idea how long its been broke as I can count on one hand how many times Ive had the hood up since Ive owned her. When I saw that I thought, there's my problem, unmetered air getting into the system causing a lean condition. After fixing it the problem did seem to be less severe but, when I had the inlet pipe off I had noticed that their was a little puddle of oil that had pooled on the inlet of the turbo itself.
My guess is that the check valve for vent tube has been stuck for a long time. When this happens an excessive amount of oil will make it's way into the intake. (As Carbon Sky said: the check valve is supposed to let air into the head, but not let oil back through at this location) I had a failure of this check valve and it did result in oil pooling at the turbo inlet as well as coating the upper charge pipe from the turbo to the intercooler. And excessive oil in the intake system may contribute to your pinging problem. It would be a good idea to take the charge pipe from the turbo to the intercooler loose and inspect the inside of the pipe. If you see a trail of oil, then I would suggest you inspect the the charge pipe from the intercooler to the intake as well. If you see a mist of oil covering the inside of the pipe: Then you need to also take loose the catch hose on the bottom of the Intercooler and see if any oil drains out (if so, I would strongly suggest you pull the IC and have it flushed/cleaned). Clean the oil out of the charge pipes and put everything back together. Double check all clamps, especially the throttle body clamp; and make sure you don't have any air leaks. A small air leak could be causing A/F issues and aggravating ping. (if you have a leaky clamp, it will eventually get bad enough to throw a P0101 code)

If you have corrected the the faulty check valve, cleaned the charge tubes and upon re-inspection at a later date find oil pooled at the turbo connection again, then you will know that you are getting excessive blow by from the second line, as Carbon Sky suggested.
 
#7 ·
My guess is that the check valve for vent tube has been stuck for a long time. When this happens an excessive amount of oil will make it's way into the intake. (As Carbon Sky said: the check valve is supposed to let air into the head, but not let oil back through at this location) I had a failure of this check valve and it did result in oil pooling at the turbo inlet as well as coating the upper charge pipe from the turbo to the intercooler. ...

If you have corrected the the faulty check valve, ...
Completely agree with all GS and CS said. As for the gummed-up check valve, I obtained a 'failed' check valve and pipe from another forum member that had replaced his. Sure enough you could both suck and blow air through it, so it was definitely stuck open. I flushed it a few times with rubbing alcohol and that freed it up to where it was completely fine and operational again. I then put the previously failed valve on my own car and not a trace of oil since, so you too can probably do this rather than buying a replacement Of course, after cleaning, be sure to check you can only blow, but not suck, through the valve (or vice versa :)).
 
#6 ·
You can check both of these lines pretty easily. The one that attaches to the plastic nipple doesn't even need tools, just twist the plastic clip release and it will come off. There should and often is the slightest oil mist in this line, but if you drops of oil, that one-way check valve has failed.

But from what I'm seeing, LNF engined kappas with raised boost 21+ often push oil out the exit line that is internally baffled in the head. This line runs down to the turbo. If you reach down to where the rubber intake hose meets the turbo, held in place by a ring clamp, and there is oil, use a screwdriver to loosen the ring clamp so you can pull that hose off and look into the intake of the turbo. If you see oil in there, it's coming from the outlet line from the head. This is where a lot of people with raised boost are pushing oil out it seems and the only way to deal with this leak is to run a breather tank or catch can.

As long as the check valve in the first line I spoke of is working properly, you shouldn't need to "upgrade" it or anything like you do with the outlet line that runs to the turbo.

I'm waiting on sourcing some high temp 3/8" EPDM rubber or silicon vacuum caps right now, and when I do I'm gonna tinker with this breather tank:




That 3/8" barbed nipple threads onto the black anodized AN fitting. That fitting attaches to a metal tube that runs to the bottom of the tank. There is stainless steel wool/mesh inside the tank, and it vents out the top. In case the LNF has issues running the heads vented to atmosphere, I will run this setup as a catch can. I will cap the top, and on the back side I will put the same AN and 3/8" barbed nipple and run it as a catch can.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top