Engine Overheated - Change Oil?

[pjf]

Is it necessary to replace the engine oil and filter after the engine has overheated?

After visiting my daughter this weekend at her college, one of my radiator hoses broke while I was on the highway heading back home. When I noticed that the temperature gauge had reached the high mark, I turned off the engine, stopped on the shoulder and called a tow truck.

The service station replaced my hose, thermostat and coolant yesterday and then advised me to replace my engine oil when I return home. They wanted to replace my engine oil immediately but knew that I was in a hurry to head back. The engine performed normally during the 300-mile return trip.

My oil and filter were changed just before the trip. Does an overheated engine damage them?

 

[RamFan]

Originally Posted By: pjf
Is it necessary to replace the engine oil and filter after the engine has overheated?

After visiting my daughter this weekend at her college, one of my radiator hoses broke while I was on the highway heading back home. When I noticed that the temperature gauge had reached the high mark, I turned off the engine, stopped on the shoulder and called a tow truck.

The service station replaced my hose, thermostat and coolant and then advised me to replace my engine oil after I finished the 300 mile drive home. They wanted to replace my engine oil immediately but knew that I was in a hurry to head back.

My oil and filter were changed just a week ago. Does an overheated engine damage them?


How long do you think the engine was overheated for? Are you using conventional or synthetic?

 

[Loobed]

Heat can damage oil. I would change it because I have a big stash of free oil. It is up to you. You probably didn't hurt the oil or the filter.

 

[pjf]

After driving about 10 miles, I heard a tapping sound while accelerating up a hill, immediately looked at the gauges and turned off the engine.

The oil in my engine is 5W30 G-Oil which is synthetic.

 

[djb]

What car and engine?

Some engines do quite badly when overheated, warping the head, leaving the head gasket brittle, and creating burnt oil deposits. Other engines just shrug off the abuse.

 

[pjf]

I have a 1989 Suzuki Sidekick with a re-manufactured 1.6-liter, 8-valve engine. The AAA service station found no head warping and no obvious engine damage. They checked the engine oil and found no water in the oil that would indicate gasket damage.

I just bought a 5-quart jug of G-Oil an hour ago to replace the overheated oil. Do I need to replace the filter? It is a Microgreen filter. I have an extra one.

 

[RamFan]

Originally Posted By: pjf
After driving about 10 miles, I heard a tapping sound while accelerating up a hill, immediately looked at the gauges and turned off the engine.

The oil in my engine is 5W30 G-Oil which is synthetic.


Hmm I would assume you were probably overheated for 5 or 6 minutes maybe? If it was only for that long I would keep it in, if money isn't an issue you might want to drain a quart and put in a fresh quart and get a uoa on what you drained. Would be kind of interesting to see what changes if any occurred with the oil.

 

[JHZR2]

Id usually say yes, but was it hot or pegged at max? Did you get "smoke" water vapor coming from the cooling system? was there any water left in there?

I might end the OCI early, but not necessarily change it out immediately. While this was an issue with grp I and II oils, Grp III has much higher oxidation resistance.

 

[pjf]

Originally Posted By: RamFan
...you might want to drain a quart and put in a fresh quart and get a uoa on what you drained. Would be kind of interesting to see what changes if any occurred with the oil.

Good idea! I'll submit the overheated oil for UOA. I'm prepared to replace both the G-Oil and the Microgreen filter.

 

[pjf]

Originally Posted By: JHZR2
Id usually say yes, but was it hot or pegged at max? Did you get "smoke" water vapor coming from the cooling system? was there any water left in there?

I might end the OCI early, but not necessarily change it out immediately. While this was an issue with grp I and II oils, Grp III has much higher oxidation resistance.

The temperature gauge was at maximum but I don't know for how long. Yes, "smoke" water vapor did come from the engine compartment after I stopped. I don't know how much water remained but the hose that busted was a small hose near the top of the engine under the thermostat.

What group does G-Oil belong in? The specifications are at this URL:

http://www.pqiamerica.com/January2012A/January2012R2/goil.htm

 

[chubbs1]

Originally Posted By: pjf

What group does G-Oil belong in? The specifications are at this URL:

http://www.pqiamerica.com/January2012A/January2012R2/goil.htm


G-Oil would be a Grp. V (Ester).

Yes I would change it, don't worry about the filter, MicroGreens are too expensive and there was most likely no damage to the filter whatsoever.

 

[demarpaint]

Another vote for changing the oil.

 

[RiceCake]

I would, mostly because oil is cheap to change. To be honest though I don't really think overheating it would "ruin" the oil any faster then it would ruin the entire engine.

That being said, I know some GM cars use a technique to deactivate injectors when the motor is overheating, or something to that effect, to encourage convection cooling with obviously reduced performance, for emergencies. They recommend changing the oil afterwards, but I get the impression this is more from fuel dilation issues from their "limp" mode.

 

[rg200amp]

Change it!

 

[dubie2003]

Considering that oil is cheap, change it. N top of that, the oil was probably FAR so.... Just change it.

 

[daves87rs]

I'd change it just to be safe....

 

[lexus114]

Agree with other poster re; just change it to be safe.

 

[Falcon_LS]

Change it.

 

[mechtech2]

It was a good thing that this happened with fresh oil in the crankcase. More margin for safety.
We are not sure if the oil overheated or not - I'd change it out and leave the old filter in there [and yes- just leave any old oil in the filter].

 

[Maxima97]

Change the thermalset and check the cooling system should be the right thing to to. At the moment, use heavy weight oil just in case.