I have researched/googled this problem several times to no avail....my engine oil is turning a reddish color with only 2 thousand miles or less on it....i change it regularly ...2003 Blazer 4.3 engine 124,000 miles,since new....noone has ever driven it but me....I use Castrol HM 10 W 30....some say it is normal,some say not? I know others have experienced this...looks almost like burned tranny fluid...tranny checks full....no additives to oil.....does not seem to use any oil tho.....some say it is just the brand oil....i started using Valvoline recently....same thing today when I change oil! almost bloody looking and viscosity seems normal,not thinned....no unusual odor,just reddish rather than golden brown ,i don't run it long enough to turn black! Transmission guy said no way tranny fluid can get in oil?? anyone have a good answer???? Thanks in advance for any experience in this issue....

 

Your transmission guy is correct. Transmission fluid can't get in there. Can you post a picture of it so we can see?

If you're really worried about it, send a sample to one of the labs that does oil analysis.

 

what Tom said and also - WRONG OIL. use 5W30 Full Synthetic of your preferred brand and type. Post picture of the oil from the dipstick spread onto a white papertowel.

 

When you say "reddish" it is not a red/brown chocolate color, is it? Is it still clear? I'm wondering about coolant getting in it.

A picture would really help.

 

okay...will post pix soon....thanks for input /suggestion

 

will do.....

 

I really don't see anything wrong with the Castrol High Mileage oil, but I would use 5W-30 instead of 10W-30. The slightly heavier oil probably won't cause any problems, though.

 

Nothing wrong with 10w-XX during warmer weather; however, you may get lower fuel economy and (theoretically) more engine wear on start-up, although I seriously doubt it would make a difference on any 20 year old American pushrod engine.

More importantly though, I believe is trying to find an oil, or mixing oils to come up with zddp levels that are very close to what was being produced at the time your engine was made. Doing this while (of course) keeping viscosity within reasonable limits as per expected weather temperatures.

Further research can easily be found online. or by browsing BITOG. Here’s a good starter for anyone that cares:

“In 1992, an API-rated SH oil contained 1,200 parts per million (ppm) of phosphorus; in 1996 SJ contained 1,000 ppm. It was not until 2001, when the rating went to SL, that we all started to see camshaft problems appear”

Quoted from here:

https://www.enginebuildermag.com/201...-what-why-how/

 

It is good to use the 10W/30 in the warm summer months and 5W/30 during the cold winter months. The 5W flows quicker in cold start ups getting the oil circulated faster though out the engine. I think part of the problem is the temptation to go for the 'extended' Oil Change Intervals, O.C.I., especially when using synthetic oil. The syn.oils are significantly more expensive and people seem to justify that extra expense by going to the extended interval. That's a bad idea. Many oil experts recommend a 3,000- 3,500 mile interval with traditional petroleum oil and 5,000- 7,500 mile intervals with Full synthetic oil. With Full synthetic oils, I would never recommend the 10K, 15 K, and more OCI you are hearing about. That is asking for trouble.
Skyray should try the FULL synthetic oils for 3 oil changes. That will help clean the red deposits off the engine internals. Take a flashlight and open the oil fill tube to see if the engine components have 'reddish deposits' on the valve train. Spend some time on the BITOG.com site and read about OCI, oil filters, and different oil brands. For example, full synthetic is different from the 'synthetic blend' or syn blend which is a mix of full synthetic and petroleum oil and less expensive.