Oil/engine problem that may require viscosity....

[addyguy]

In the November, 1972 Issue of Popular Science, there is a large add for Shell's new 'Super X 10W-50' multi-viscosity oil. In the add, it states the folowing: (quoted verbatim)

"Hot cranking performance is a good test of an oil's ability to hang in there"
"Ever stopped an engine after a hot run, then noticed how slowly it cranked when you fired up a few minutes later?"
"While the engine was sitting there cooking, oil between pistons and cylinder walls thinned so much that rings dragged against the walls with high friction, and overloaded the starter"

In my 2002 Chevrolet Cavalier 2.2 OHV engine, I have this problem all the time. After driving for moer than 30-45 minutes or so, when the engine is good and hot, if I try to start it within 10 minutes of shutting down, it will do this. The engine will start to crank, and then will suddenly 'seize' for a couple of seconds, and stop cranking with a very strained sound.

I usually stop cranking the engine, give it a couple of seconds, and try again. It will start, but it still cranks slowly, and a couple of times I've had to use the gas and rev it a bit to get it going. I thought what I was getting was fuel 'vapour lock' from hot fuel in the FI system, but vapour lock shouldn't affect the actual engine cranking speed. It never does this when the engine is cold, or if it has definetly been sitting for more than 20 minutes.

Another reason I think it could be this is that my 2.2 OHV engine is defintly an 'old school' engine design that has more in common with a mid-1970's Chev 350 than a more modern engine. It has bad piston slap when cold, and even some when warm, so its not out of the question that the pistons would 'wedge' in the cylinders, and not move b/c of too-thin oil. I use standard 5W-30 dino in the engine, and it doesn't matter how 'old' the oil is for this to happen.

I'd like to make it clear that I know that an early-1970's 10W-50 dino oil is miles away from modern PCMO's, so I'm not saying I should run out and find 10W-40 or 20W-50 for my car, especially with winter coming up. But it would be interesting to see if running a thicker oil will stop this, something like a HM 30-weight, GC 0W-30, or even M1 0W-40.

Thoughts?

 

[gfh77665]

ONLY use 0-20. Thats what almost everyone here will say. (rolling eyes...)

 

[d00df00d]

Any good modern xw-30 synthetic should help greatly. Give it a shot!

 

[bepperb]

"ONLY use 0-20. Thats what almost everyone here will say. (rolling eyes...)"

If you don't like the people around here, why hang aroud here?

But back to the topic at hand, that's an interesting phenomonon and a reasonable theory. But I don't see how the oil's normal viscosity will have much effect on it... heated to the temps of a piston or cyliner wall and they will all be incredibly thin. It'll be interesting to hear what some more knowlegeable people have to say, but from my seat I don't think viscosity will have much to do with it as engine design or the oil's volatility. Perhaps an oil resistant to very high temps would help?

 

[il_signore97]

addyguy,

The issue with your hot starting problem could be traced back to the starter. Not that the starter itself is bad, but after a good hot soak for a few minutes, the starter picks up too much heat. Once overheated, it will not be able to properly start the engine, causing symptoms similar to those you describe.

I've seen this happen to a few older Chevy 350's. A friend of mine actually has a motor home powered by a Chevy 350, and you can imagine the heat that it can produce. His problem is so bad that he actually carries a spare starter. If a hot restart is required, a quick starter swap allows him to start the engine with no issues. But after a hot soak, it won't even crank. It will take over an hour of cooling to even get the engine to turn over a bit without the starter swap!

Just a thought - not sure if this is acutally your issue...

 

[Gary Allan]

Those types of starting issues can be anything from fuel percolation due to carb issues (in the referenced publication - the 70's) ..to the starter being heat soaked ..to, in some engines, piston expansion with lack of sustained cooling.

I'd put oil at the lower end of the list. Doug would have the highlights somewhere in his personal mental archives.

Your situation shouldn't be fuel related. I agree the starter or some firmware timing issue is responsible.

 

[addyguy]

I really, really don't want this thread to turn into a 'thick vs. thin' debate. This oils have been working perfectly fine in many vehicles for many years. It's just possible that some engines or engine problems may respond to viscosity, and i think an 'old school' style OHV engine is one of them.

Truthfully, as I was podering this situation, I realized that a synthetic 30-weight oil is most likely the answer. All of them will have the increased film strength to hopefully aleiviate the problem. If I really want to go overkill, Redline 5W-30 come to mind, with it's 3.6 HT/H value. As I said, I'm not going 'stupid' and starting to run even a 10W-40 in a Canadian winter. But a 5W-40 or 0W-40, sure!

 

[il_signore97]

If you want to rule out the oil issue, go grab some M1 0W40. It will perform well in your engine in both the summer and winter. So if it fixes the problem, great, if not, look into other issues that have been posted up here.

 

[addyguy]

Thanks for the ideas and discuission everyone.

In being 'realistic', this, as a couple of people have suggested, is most likely a starter 'heatsoak' problem. Even when thinking about this, I had a hard time believing that a modern, SM/GF-4 5W-30 would allow 'heat seizing' to occur in the engine.

 

[Drew99GT]

That's an article from 1972 when motor oil was much more volatile and less shear stable.

I doubt a modern SM/GF-4 oil is the cause of hard starting in a Cavalier!

I totally agree with Gary here.

We put WAY too much emphasis on oil and possible oil related engine problems on this website IMO.

 

[Nickdfresh]

I have this problem with the exact same engine. I've helped it quite a bit by changing out the crank-sensor located above the drain plug on mine. It was a pain in the butt as it's tough to get any leverage on it through the frame, but it definitely made a positive difference but has not totally solved the problem. Also, using Bosch Platinum+4 plugs (the car calls for platinum plugs and I previously used regular NGKs -do'h!) helps a bit.

I don't think oil will make much of a difference here although I think the car runs a touch better on "thinner" 5W-30 weights, currently I have 5W-30 QHP syn and plan on doing a UOA on it sometime in November or December. I don't really notice any "piston slap" though, and think the car is probably not really comparable to something out of the 70s and is somewhat crude, but more refined than GM's previous '4-Tech' engines...

 

[Nickdfresh]

Incidentally, after reading more of the posting, I've previously used 10W-30 Mobil1 HM and MaxLife in the same weight with no discernible differences in regards to hard starting when warm. The problem is almost certainly electrical and far less noticeable in colder months...

 

[il_signore97]

No problem. Definitely doesn't hurt to try the 0W40 though. At least you can confirm if it is or not an issue, then go from there.

 

[BuickGN]

I would definately like to see the results. I experienced the same thing and never really got an answer. My father was on at least the 10th dyno pull of the day, everything was heatsoaked and immediately after an 800+rwhp run he accidentally killed the ignition instead of letting temps stabilize. I know some people do this and get away with it just fine. But he restarted after a minute and it barely turned over. The interior lights dimmed like the starter was under a ton of load. This car was driven like this for an entire summer and in normal driving this never happened, only the one time on the dyno. I've very curious to see the results of a good synthetic in the Cavalier.

 

[Nickdfresh]

Originally Posted By: il_signore97
addyguy,

The issue with your hot starting problem could be traced back to the starter. Not that the starter itself is bad, but after a good hot soak for a few minutes, the starter picks up too much heat. Once overheated, it will not be able to properly start the engine, causing symptoms similar to those you describe.

I've seen this happen to a few older Chevy 350's. A friend of mine actually has a motor home powered by a Chevy 350, and you can imagine the heat that it can produce. His problem is so bad that he actually carries a spare starter. If a hot restart is required, a quick starter swap allows him to start the engine with no issues. But after a hot soak, it won't even crank. It will take over an hour of cooling to even get the engine to turn over a bit without the starter swap!

Just a thought - not sure if this is acutally your issue...


This sounds very, very plausible. These 2.2LOHVs are also notorious for having bad "crank-sensors." The good news is that they're like a $10 part at Autozone. The bad news is that they're a bear to get at, but can be done while the car is propped up for an oil change...

*Incidentally, my main worry from excessive cranking is fuel-dilution. But since I pound miles on this car at the rate of at least 60 hwy. miles a day, I was told not too worry about that too much...

 

[mechtech2]

The starter is my first guess, also.
This was a huge problem on GM engines in the past, and they installed heat shields to attentuate the problem.
Heat causes resistance to go up, and there are problems [except for carbon].

 

[CATERHAM]

I agree it's not motor oil and sounds like it's part of the starting circuit. In addition to the starter, it could simply be a bad ground or battery connection.

While I'm almost certain it's not engine related to eliminate it in the diagnosis simply pull the spark plugs and the engine should turn over easily by hand.

 

[gfh77665]

Originally Posted By: bepperb
"ONLY use 0-20. Thats what almost everyone here will say. (rolling eyes...)"

If you don't like the people around here, why hang aroud here?


Oh, I get it: The "thin guys" can ridicule and nuke anyone who dares to disagree with them, but any thoughts to the contrary the message is "hit the road!" huh?

Ain't gonna work. I have done nothing wrong, and I am not going to be bullied into leaving by "thin guys", not by a long shot!. This is an open forum for thoughtful expression on the subjects at hand. I'll be here.

 

[river_rat]

Interesting.
I started driving in 1981, and owned a number of 70's cars and trucks including a '76 Camaro RS with the 350.
I never had a slow crank when the engine was hot on any of them.
...Just saying I've never experienced or even heard of this phenomenon.

 

[BuickGN]

Originally Posted By: gfh77665
Originally Posted By: bepperb
"ONLY use 0-20. Thats what almost everyone here will say. (rolling eyes...)"

If you don't like the people around here, why hang aroud here?


Oh, I get it: The "thin guys" can ridicule and nuke anyone who dares to disagree with them, but any thoughts to the contrary the message is "hit the road!" huh?

Ain't gonna work. I have done nothing wrong, and I am not going to be bullied into leaving by "thin guys", not by a long shot!. This is an open forum for thoughtful expression on the subjects at hand. I'll be here.

Agreed.