Engine Rebuild

What Oil Would You Use In A Fresh Rebuilt Engine. Synthetic 10w30 Or Reg 5w30

And Is Dex-Cool Any Better Then The Green Stuff As In Cooling And And Build Up. When I Cleaned This Engine I Noticed Alot Of Green Build Up That Settled At The Bottom Of The Engine.

This Is In My Grand Am 2.5l
Thanks

 

reg oil for now and then synthetic later 500-1000 miles then change to what ever you want for oil, and the dex cool extended life is a little better shouldnt build up

 

Ditto. Use a cheapie 10W-30 or 5W-30 non-synthetic oil, preferably a diesel rated grade. It has more of the additives needed for break-in.

 

If your engines has roller lifters you can start it off on synthetic oil. If engine break-in was a problem with synthetic, vehicle manufacturers would not use it as a factory fill. I have run many engines from new with synthetic oil and it is not a problem. If you are breaking in a new flat tappet cam and lifters you might want to add a can of GM Engine Oil Supplement to protect the cam and lifters during break-in.

 

Synthetic oil is not the best for break-in. It won't hurt, but it's no the best. You actually want some scuffing to occur in the engine to burnish the mating wear surfaces during break-in.

Synthetic is used for factory fill for reasons other than technical. The manufacturer may be promoting their vehicle image, as a way to say, "Our engines are so refined, that we specify synthetic motor oil". Plus they know how people hate to bring their cars in for service, and this is one way to extend the change intervals.

Ideally, vehicles should be run with regular oil during break-in and changed out early, 500-1000 miles. Afterward, synthetic is fine.

 

ok thanks for all the replys. i got the oil down now i got some more questions about dex cool. is there anything i should do before putting dex cool in, the cooling system has been washed out with water

 

If you used tap water, displace as much of it as you can with distilled water. Before refilling coolant, empty as much water from the system after flushing as possible. This includes the overflow tank. Add the proper amount of antifreeze to make a 50% solution calculated from the specified capacity of your system. Then top off the remaining charge with distilled water.

Over the next few days keep topping off the cooling system untio all the air is burped out of the system.

 

i was thinking about going with pure dex-cool because it can only protect to -34 and the last couple days it has been way bolow that

 

you dont need to use distilled water nobody does that (not even dealers) and cannot use straight pure dex or any antifreeze straight it will not have the same properties as mixed and will not do an effective job cooling the engine

 

anti-freeze is actually more prone to freezing full strength than if diluted. In other words, follow the directions on the jug.

a 70% solution (30% water) gives you freeze protection to -84f. If it gets colder than that I don;t know what to tell you.

also realize as of late last year there were at least 14 lawsuits in various state and federal courts with the possibility of one of them becoming a class action suit concerning the effects of dex-cool in GM engines and the repairs it is being blamed for.

Other than that, I understand mixing ethylene glycol anti-freeze and Dex-cool results in jelly.

I don;t know what concentrations of either would be neccessary to cause this reaction but it would tend to make me want to flush anyplace the old stuff may be with a chemical flush prior to using dex-cool. Sometimes I am over reactive but I don't like jelly in my engines.

 

my van is doing a damn good job cooling with straight aintfreeze, it cools alot better then when it was mixed

 

Good for you, but keep in mind that pure antifreeze freezes at +10°F and has half the thermal transfer properties of water. Please don't post information that would mislead others into thinking it's okay to run pure antifreeze.

 

why hasn't mine frooze then its -20 right now, and the tester said it can protect to -60, and has a boiling point of 320

 

I don't know why your fluid hasn't froze, but the fact is that pure antifreeze freezes at +10°F.

 

Are you sure it is pure anit freeze? I've noticed over the last several years they have been packaging already mixed anti freeze. The price is cheaper but hey, I can supply my own water cheaper

 

it says theres no water added

 

I would bet you still had some water in the egine block.

 

it was in a rebuilt engine, everything was dried one even the heaters, they were both brand new

 

ah....a anti-freeze war.

We all know that mixing anti-freeze and water is the proper way to do it.

Keeping it straight anti-freeze can and will void manufacturers warranty if a problem should arise.

Play it safe, and mix.

 

Don't take our word for it. Here is a link from the University of Fairbanks Alaska.

http://www.gi.alaska.edu/ScienceForum/ASF6/680.html

You must have some of that special "magic" anti-freeze that all those chemical engineers know nothing about.

 

maybe because this aintfreeze has %60 glycol. this is just some cheap stuff from target, peak i think the brand is. the jug that has been sitting out side, isn't froozen

 

A high school buddy of mine, "Mr. Scientist", decided he would run pure antifreeze in his car. It wasn't long before his car was blowing a white cloud from a cracked block, and he ended up scrapping the vehicle.

 

i been driving it this way for 2 years, but i dont know, i took it in and had the aintfreeze checked and they said its really good, they even took some out and tryed to freeze it and it wouldnt freeze

 

I'm sure you saw the link nap provided. This raises two questions. How much water was left over in the cooling system (engine, radiator, heter core, hoses) before you refilled? How much water was in the antifreeze jug as purchased? I doubt the answer is zero for both questions.

 

i know there wasnt any in my van because the whole cooling system was brand new, and the engine was just rebuilt, i'll check the jug and see what it says

Material CAS# % by Wt PEL (OSHA) TLV (ACGIH)
Ethylene Glycol 107-21-1 90 - 97 50 ppm 50 ppm
Diethylene Glycol 111-46-6 < 5 None None
Hydrated inorganic acid, proprietary < 5 10 mg/m3 1 mg/m3
organic acid salts
Water 7732-18-5 None