[Big Dan]

I did this mod over the weekend, and I did not see a bypass valve. I wasn't really looking for one though.

Then the bypass valve must be in the oil cooler adapter itself...
It's an important feature in case the filter plugs up, for my part I've never seen this happen but nevertheless
if theres no bypass valve under the oil cooler adapter instead of switchin nipples,
I'll probably buy a filter adapter (oem or equivalent) such as the one on this pic, anyone can confirm please ?
And still, thanks for your reply aquazen

 

[AstroWill]

Then the bypass valve must be in the oil cooler adapter itself...

No, it's in the block.

 

[AstroOafAdventurer]

I had been keen on removing mine being I like the fact less to go wrong. Evidently I hadn't read the whole thread when I first saw it some time ago; now I'm thinking of leaving well enough alone as I don't recall the bit about additional cooling especially in the heads.
My lines have noticeable caked on oil/road grime but yet to see a drop under it but foo sho looks like something has leaked previously in the general vicinity.
Although, aside from not driving it much, no idea what the PO has done to it.

 

[aquazen]

I had been keen on removing mine being I like the fact less to go wrong. Evidently I hadn't read the whole thread when I first saw it some time ago; now I'm thinking of leaving well enough alone as I don't recall the bit about additional cooling especially in the heads.
My lines have noticeable caked on oil/road grime but yet to see a drop under it but foo sho looks like something has leaked previously in the general vicinity.
Although, aside from not driving it much, no idea what the PO has done to it.

My engine bay is absolutely covered in grime, which is one of the main reasons I did this mod. When everything is covered in 1/4" of grime, it not only makes the work harder, it also can help hide issues.

 

[AstroOafAdventurer]

My engine bay is absolutely covered in grime, which is one of the main reasons I did this mod. When everything is covered in 1/4" of grime, it not only makes the work harder, it also can help hide issues.

Amen to that brother. Nothing worse than going in for something basic and coming out greasy grimy. Mine isn't too bad, definitely better than some vehicles I've owned. I have noticed some accumulation in areas I wouldn't expect from the oil cooler like around the air intake box and the valve covers noticed today. Not much there but enough to hmmm. But otherwise anytime I go in arm deep I get something on it lol

 

[Big Dan]

No, it's in the block.

Thank-you for your answer AstroWill !

 

[gwd]

When I had my 1981 Jimmy/Blazer with small block Chevy V8, it came with oil cooler line option like the van does.
When the old cooling lines rusted out I removed the cooling line adapter.
Inside the cooling line adapter the pressure relief valve part like shown above was screwed in.
I removed the oil pressure adapter from line part and screwed back into block and the center treaded oil filter nipple.
I looked into the GM Shop manual and there is no mention of an oil pressure relief valve inside the van block.
Looking at the pictures above, it looks like the oil pressure relief valve is built in the oil cooling line adapter.
Can someone who has removed the cooling line adapter look into the housing and see if it is in there.?

 

[astrohutt]

It is a big pain in the butt changing out those factory lines and they run about $100 for both upper and lower lines.
The thought has crossed my mind about just eliminating the factory spaghetti noodle set up and just mounting an after market oil cooler underneath 1995 Astros do not have the oil line connecter your pics show and have two separate lines with threaded fitting on the filter adapter. If you make two short tubes with hose clamp ends off the oil filter adapter and run high pressure hose to a bottom mounted after market oil cooler you would still retain oil cooling and save the headache of replacing the pain expensive and difficult to change factory lines running into the cramped engine compartment.

 

[Sailing_Faith]

Unless you are running some old oil from the 1970s, you really don’t need an oil cooler.

 

[astrohutt]

In my honest opinion, An oil cooler is a wise personal choice unless you live in cooler areas. We live in the blistering desert and CHOOSE to be smart enough to use one regaurdless of what oil you use. BTW We run synthetic oil in all our vehicles.

 

[Sailing_Faith]

It’s an opinion that makes sense until you realize that most of the 4.3s fit into other trucks and vans did not have them. Full size trucks with higher towing ratings…

When the Astro was drawn, the engineers were concerned about the more compact front end… The SAE standard for oils had changed a long time before, but the engineers were concerned about coking…

Was never a problem…. Even less likely with todays oil.

What absolutely IS a problem is losing oil pressure because the oil cooler lines part. Even the ACDelco lines can and do fail.

 

[AstroCharles]

Thanks for the well-illustrated and well-written instructions! I am almost two years since deleting oil cooler lines with good results. In my case, I had leaks at the hose fittings. Since deleting, I have seen no difference in engine temperature, and oil pressure is a little better (higher.) We live in a northern state and don't get much hot weather. Our towing is occasional light utility trailer. I thought I had modest oil consumption of about a quart between changes, but now that the leak is fixed it turns out it isn't burning oil at all. I'm using whatever synthetic blend oil is on sale at Fleet Farm. One more thing, winter is 5W-30, and summer 10W-30 (per owner's manual, 5W-30 is preferred year around, but 10W-30 is OK for above zero F.) My thought is to have the slightly thicker oil in summer. Our Astro is 2001 RWD with about 150K miles, driven more highway as a second car.

 

[Mmusicman]

It was always my understanding that the 2nd number is the weight hot.
Since both are 30.. it seems both would be the same weight hot... 1st number less relevant in summer.

I'm in Florida.. I run 10w40 synthetic year round (older engine 260K).
I also deleted my oil cooler years ago, and my older van didn't come with one.
Neither did anything I've ever owned prior

 

[MechBob]

Generally,oil coolers are good, but not necessary for a lot of owners. Is nice having that extra qt of oil in the system. There are pros and cons, could be a long discussion,lol, and I don't much care. If winter van hoses spring a leak, probably will bypass. But summer van? Nope, as I like to hit the highway and cruise at 80+, and is usually in hot weather, or heading south.
But, kinda disagree with Sailing, as far as I remember, ALL 4.3's in Astros, after carbs and TBI, had the cooler, and possibly the other trucks,also.