OMG It Runs

Don't use 5W-40 in your 6.0 or 7.3 unless you like replacing IPR's and Injection pumps.

Seriously, someone on here or another forum told a guy to use this crap in his 6.0 550 and guess what it killed it.

So don't do it, just use normal old 15W-40.

nath1142

What proof do you have for this? My 6.0l had 5w40 in it since over owned it and it has 325,000km on it. I live I'm Canada where 15w40 doesn't work in winter for me

jcain

Your comment has no basis and the injection pump issue is actually biased TOWARDS using a thinner 5w-40 (synthetic) oil . So you're bass-ackwards in your own recommendation. The coking and thickness of 15w40 is actually what ruins the spool valve in the injectors. 5w-40 has a much wider spectrum (temperature) usage than 15w-40. My very own UOAs showed 5w-40 to have much less metal wear than 15w-40 with same pattern driving and conditions.

OMG It Runs

Mainly because I recently did a totally non related repair to the same engine which had been running 15W - 40 for many a mile. All I did was replace the EGR cooler and intake gaskets.

The customer requested his oil be changed to 5W-40, and a week later his truck just quit running.

When the IPR valve was pulled for inspection, it was found that it was completely melted and bashed to nothing. The injection pump would only put out 325 psi during cranking which is nothing because you need at least 500 to get the motor to start.

Seems a little sketch if you asked me...

And as far as the spool valve thing you need a thick oil to keep pressure up so the injectors will fire correctly. That synthetic stuff might work great but get it hot and its the consistency of warm milk which will cause crap pressure to the injectors and possibly just make your motor cut off.

jcain

Again, you're backwards. I'm sure you can read up on oil analysis studies yourself.

snobdds

What are you talking about. If the ipr was messed up its because someone let dirt into the hpo system. Probably doing the oil cooler and egr. Synethic 5w 40 is he oil that one should run in the 6.0. Plus is better for the injectors. I think you should read up more on this...

OMG It Runs

That is something I cannot possibly deny, since I did the work. That is a possibility I had lightly considered but its hard for me to believe a little piece of carbon would kill a pump like that. The entire top half was chrome clean, I mean you could have eaten out of the intake valley it was so clean before I took stuff out.

But nonetheless, I'll read up on it. It just seems awful darn thin.....

I have to admit there are a lot of variables introduced here being that the engine had previous work. I don't guess it would take too much dirt to mess stuff up....

Thanks for the heads up! I work on a lot of 6.0's :-)

snobdds

A little piece of junk can mess up the IPR. There is a plunger in there that, if not seated all the way, will cause a HPO leak. A little junk can get stop the plunger from seating. Most of the time a little break cleaner will blow out the junk and the valve will seat properly again. Most of the time an IPR can be diagnosed with a gauge. If the IPR is pegged at 85%, then there is a HPO leak and the injectors can't build pressure.

IPR's always see to fail after a oil cooler replacement...

canadianguy

Sounds like you messed up his truck.