Engine Oil Cooler Lines (Engine Side)

[west85]

Just wondering if anyone knows the the newer 5/8" ID lines have the same fitting on the engine side as the earlier 1/2" lines and if the 5/8" lines would work on my 96 6.5TD.

Thanks!

[More Power]

I haven't experimented with them, but I'm told the fittings and lines are not interchangeable....

[6.5TDTahoe]

The late.5 engines have larger holes in the block for the OC fittings .No way to fit or adapt early & late.

[Robyn]

These are mutually exclusive items.

The lines and fittings must match the block being used.
The larger lines/fittings used on the later blocks can't be used on an early one and vice versa.

Best plan is to use an aftermarket cooler and braided lines with JIC fittings.

The factory lines were/are prone to leaking after they get time on them.

Its not a big deal to change to a universal cooler with the stainless braid lines.

Missy

[rameye]

I just dealt with this during my engine changeover...

I had brand new factory lines, adaptor hardware and factory cooler costing me quite a bit...to my chagrin the new engines' holes were too big.

I purchased some brass bushings...installed into block and used all my new/old parts. It all fit up nicely...no issues.

I realize that I may have reduced my oil cooling capacity somewhat...it was just too late in the game to spend another $500.

So yes you can adapt the older stuff to the newer block....but it is not without penalty.

Robyn...dont kick my butt too bad.

[JohnC]

The newer blocks have the piston oil spray nozzles and tghe high volume oil pump. this is why they also have the larger oil cooling lines and fittings. If you put reducers on them you are restricting the flow from the design.

[rameye]

Yep...

But will the penalty be cooling capacity loss or something more sinister...??

I dont tow...the truck pretty much has an easy life..

Your thoughts?

[6.5TDTahoe]

Piston oilers, 6.5 running change in 1997 & 5/8 lines 1999. The newer larger lines may actually measure @3/4. GM & Dorman supply both sizes.Big price on the OEM's!!

[JohnC]

Yep...

But will the penalty be cooling capacity loss or something more sinister...??



All the oil passes through the cooler, or the cooler bypass valve, which is actually a pressure relief valve. Either way, more pressure == less flow. Not sure how sinister, though...