ECT too cold?

[hquick]

What would be the effects of running a motor too cold?
I'm starting to wonder if that's a problem for me.

[joecar]

Howard,

If too cold (off the top of my head):
- if running CL, it may not ever enter CL;
- ECT based fueling tables may cause running rich;
- auto trans may never apply the TCC;
- combustion will not be as efficient;
- if running cats, they won't be as efficient;
- condensation accumulated in block will not eveporate off, causing problems with oil;

(I didn't view your file as I'm on a PC which won't allow me to install software.)

Cheers,
Joe

[cmitchell17]

My truck just did that and I just changed the thermostat.

In the summer it did not seem like a problem, but in the winter it would never warm up and get a max of like 180. Now it runs at 205-220.

My oil cap has wierd looking yellow stuff on it so I guess its just from running cold and not getting hot enough.

[hquick]

Thanks Joe,
I might swap back to the stock thermostat this weekend and see if it makes any difference. I'm currently running trhe 160o stat.
I get pinging at what seems to be cooler temps...(first thing in the morning) and I often see 10's on the AFR guage and logs...yet I never command it.
Freeway driving is around 70 - 75oC. What is considered 'normal'? I was thinking around 90 (think that's what it used to run at).

Cmitchell17...I'd be looking into your coolant levels and keeping a REALLY close eye on them if I were you.
What vehicle do you have (wish everyone would list that info in their sig/profile).
Is it a yellow jelly looking substance?

Thanks

[joecar]

Howard,

90C (194F) is good.

70C-75C (158F-167F) might be ok for 1/4 mile drag racing (after motor has been warmed up), but I don't think it's good for a daily driver.

I read somewhere that overly rich may also induce ping, but I don't really know.


Cmithchell,

I agree with Howard, Dexcool manifests itself as an orange/yellow jelly/goo when it shows up in places where it doesn't belong... keep an eye on yuor coolant level;

Normal condensation inside the block, if engine heat fails to evaporate it off, mixes with the oil and you will see a dark brown goo (possibly with white streaks thru it) on the oil cap and under the valve covers; sometimes may look like chocolate milkshake... however, other fluids can do the same thing: ATF and power steering fluid (if you have a factory PS cooler); when changing the oil, this goo stuff may or may not drain out; so regularly keep an eye on all fluids.

[hquick]

Thanks Joe,
I'll swap the stat tonight.
I've also heard that too cold will cause too rich and therefore 'pinging'.

[cmitchell17]

How could rich cause it to ping?

About the coolant thing, im kind of confused on what you are saying. Are you saying I could have blown a head gasket or something causing dexcool to be getting into the crankcase? Im still using dexcool on my 5.3 as far as I know at 130k I got it at 120k.

[cmitchell17]

I know this is kind of off topic but how can I get this stuff out of my engine?

Im running wal-mart brand synthetic (its 2 dollars a quart) after I saw on a GM presentaion about oil that it was approved by gm.

Will it just come out now after changing my oil?

I don't know if I have a factory ps cooler or trans cooler, anybody know the rpo codes to tell? I don't have a towing package.

[hquick]

I'm fearing you may have a blown intake manifold gasket and that's allowing coolant into the oil. If it's so...you need to fix it ASAP so you don't wash your bearings and end up needing a complete rebuild.
I'd try an oil change if I were you and just keep an eye on it.
I don't know how 'too rich' causes ping...but I've heard this from alot of sources.

A factory PS cooler looks like this:

Far right hand side of the pic of my grille...about 10" long and 2-3" wide.

The other two coolers are my trany coolers. You might have a single cooler installed in the same manner as one of those.

http://img.photobucket.com/albums/v35/hquick/4L60e%20to%204L80e/P9290001.jpg

[joecar]

How could rich cause it to ping?

About the coolant thing, im kind of confused on what you are saying. Are you saying I could have blown a head gasket or something causing dexcool to be getting into the crankcase? Im still using dexcool on my 5.3 as far as I know at 130k I got it at 120k.It's something I read someplace... running excessively rich may cause knock at low RPM... I don't know what to make of it.

[cmitchell17]

Ok thanks, I noticed that today actually I was wondering what the long cooler was so now I know, but there is a big cooler in front and the radiator in back also and its the same size as the radiater.

Also ive got a 5.3 so no intake manifold with coolant running through it.

[joecar]

I know this is kind of off topic but how can I get this stuff out of my engine?

Im running wal-mart brand synthetic (its 2 dollars a quart) after I saw on a GM presentaion about oil that it was approved by gm.

Will it just come out now after changing my oil?

I don't know if I have a factory ps cooler or trans cooler, anybody know the rpo codes to tell? I don't have a towing package.You would have to diagnose the cause... it could very well just be condensation forming yukky goo under the oil cap... or it could be otherwise... the point is: diagnose it;

For example, keep an eye on your coolant level... each morning before starting up, it should be at the same exact level in the overflow reservoir... if it's not, does it ever come back up to the same level...? or do you have to keep adding coolant...? that would be the starting point; how hot does your ECT read...? does your engine get sufficiently hot to cause block condensation to evaporate off (takes a 30+ minute drive to do this); thermostat has to get quite hot to the touch;

Can pressure test the cooling system (take cap off radiator, pump up to 20 psi with the test kit's hand pump, pressure should hold for more than 1 minute; can also measure pressure when hot).

Take a peek inside the valve cover thru the oil cap hole as best as you can, see if you can see any goo in there; what shows on your dipstick...? when you change the oil, what is the appearance of the oil...?

When Dexcool turns to gel, it looks similar to a yellow/orange "grease"... it seems to do this when it "contacts" air... (but it doesn't seem to do this inside the overflow reservoir)... that's how I found my coolant leak, there was a trail of orange grease from the pump weep hole going down the front cover and accumulating on the bottom pan front bolts.

[joecar]

Factory PS coolers: in some applications (like F-body for example) the PS cooler uses engine coolant to cool the PS fluid (the cooler is in-line with the upper radiator hose... I wonder how GM dreamt that up)... if the exchanger ever leaks, then the fluids cross each other's domains.

Same thing with trans fluid cooler, if it's the one in the side of the radiator, then it may leak.

Howard's PS cooler looks like it's isolated from the engine cooling system... looks like it's purely air cooled... would that be right Howard...?

[hquick]

Yes Joe.....that's correct. PS cooler is completely seperate from anything else.
I have the 'in-tank' trany cooler as well as the two external coolers.
The large cooler you're talking about mitch would be the A/C cooler.

[hquick]

Just checked some of my old logs from back in about June. I was running an average ECT of between 95 and 98.
I'll swap the t/stat and do some more testing.

[cmitchell17]

My oil looks fine to me just a little of that yellow foam stuff and also some of that red rust looking stuff on the oil cap too.

[joecar]

I've seen the red rust looking stuff before on other motors, but I don't know what causes it
(could be caused my moisture induced rusting of iron parts that never get touched by oil...???).

Keep an eye on your coolant level, and drive the truck about 30+ minutes each day to get rid of the goo.

[cmitchell17]

Yeah thats the problem for me my trip in the mornings are only like 5-10min. It warms up fully but isnt driven for 30 min.

[hquick]

Well....I just ran a couple of logs after putting the stock thermostat back in.
Have to say....seems to run ALOT better.
Didn't notice any bucking whatsoever and no 'audible' ping.
I set the knock tables back to stock as well and had to reset my fan settings.
Here's a log from the run home from work.