89pickupsr5

I purchased the medium duty engine oil cooler from flex-a-lite and they say to sandwich it in between the block and the oil filter. there is already an oil cooler on my 94' 3vze from a 4runner that still works, but I thought this would help keep things cooler in light of the HG failures. I have the plate from an 89 pickup to block the oil cooler off so, either way i'm covered but, here are my questions:

-is the external oil cooler even better?

-would it be good to run both the stock oil cooler and the aftermarket?

of course any and all experiances, advice and, thoughts are greatly appreciated

Thanks, Drew

FredTJ

Return question for you

What are your oil temps now ?
If you don't know, then you don't know if you need an oil cooler or not.
If you're currently not getting the oil up to it's operational temperature, then an add on oil cooler isn't going to help you one bit, and may possibly hurt you.




Fred

mt_goat

Yeah, first install an oil temp gauge to see what you got. I did on my 5VZ and found my oil temps were hotter than I wanted (around 260 F). This is what I did:
https://www.yotatech.com/forums/f160...5/index23.html

FredTJ

Holy poop, I'd say it was a little hot




Fred

mt_goat

That was the hottest I saw it, with the oil cooler now it runs much cooler. The stock oil cooler is cooled by the coolant, so if the coolant is running hot the oil will also be hot.

FredTJ

Designed operating temperature for the engine oil is 212*F.
Any normally cooler or hotter temps would require a change of oil viscosity




Fred

mt_goat

Interesting... Toyota gave us a coolant temp gauge that doesn't move from the middle of the normal temp range until about 240 degrees F. So you could have your coolant up to 235 F and it still shows smack dab in the middle of normal (like everythings fine you idiot... don't worry) They designed the oil cooler to be cooled by the coolant, so that's the coolest it can possibly get. But the oil is suppost to be 212F, great. No wonder they blow gaskets all the time.

89pickupsr5

this all sounds great to me. I love Yotatech. I didn't fire her up yet but when I do there will be an oil temp gauge on board. I'll see how cool she runs with the stock cooler. I really wish I had the dough for headers which is why I'm trying to do everything I can to help on that note. I didn't really think it would drop the temp. much, just help my baby run easier, I really appreciate everyones' help on here and I'll let you guys know how my 3.0 turns out.

86tuning

I was taught a long time ago that

< 160F = cold
180-220 = warm
240 = hot
> 260 = damn hot

However, with today's synthetic oils you won't have problems with stuff in the 240 range. Our track car runs 240-260 all day, and the oil stays clear and yellow.

+1 for an oil temp gauge before doing any oil cooler modifications. You can run both an air-oil cooler in addition to the oil-water cooler (which gives faster warmup in cold weather) if needed. Actually, if you go ahead and install a sandwich plate, make sure you use one with a good thermostat built into it. Mocal SP1-T is a good unit, we've used them on our track cars before.

Also, AN oil fittings and hoses are not over-rated, just overpriced but we use them anyways. Remember that if you have an oil leak in the cooler circuit, it will spray oil everywhere because the oil is under pressure. You'll run out of oil before you know it. We use -8AN or -10AN for all of our oil coolers on the track cars. We also use Mocal or Setrab or Earls oil coolers, not the cheap stuff which tends to crack and leak a lot sooner.

FWIW, our thoughts on 3VZ HG failures seems to be a combination of y-pipe at the back of #6 overheating that area, plus it's the furthest from the waterpump, and if you're slightly low on coolant, that part fails first. So if you change any of those things, you'll reduce your chance of HG failure. ie, headers that run down instead of crossing behind the heads, or even a hood vent to cool that area. And check your coolant levels and replace your rad cap yearly.

mt_goat

That's good to hear, I think that's what I used. Mocal Part # OTSP1

Yeah I've been running Mobil 1 5w30, with the oil cooler the hottest I see is around 225-235 F.

FredTJ

The problem with high oil temps is not (at least immediately) a problem with "cooked" oil or anything like that.
It's concerning the change in measured thickness.

What in the heck do y'all race ?

While synthetic oils behave better, they still change in thickness.
Both mineral and synthetic oils "thin" at about the same rate when over heated.
A 30W mineral oil at 300*F will have a thickness of 3 cS, that's way too thin.
A 30W synthetic oil at 300*F will have a thickness of 3 cS, that's way too thin.
No difference.

Virtually every engine that most are likely to encounter are designed to use an oil with a thickness of 10 cS.

The only way to know for sure if you're wearing your engine more than you should be is to install an oil temperature and an oil pressure gauge.
You need to know what temps you're running at.
Virtually ever engine anyone here is likely to encounter is made to run oil at a certain "thickness" at an operating (oil temp) temperature of 212* F.
one huge advantage of synthetic oil over mineral base oil is it's ability to lubricate at startup.



Fred

mt_goat

What's a 30W thickness at 230 F?