Thick or thin, Ford 302, thoughts wanted.

[Gokhan]

Originally Posted By: 28oz
Been reading and thinking about an experience I had with different viscosity oils. A while back, I had a 1994 Ford F-150 with a stock 5.0/302 and ~190K miles. I ran a dino 5w-30 in it. It was our beater/camping 4x4 and I decided to put Maxlife 10w40 in it. As soon as I started it up, it made some pretty horrible noises. I shut it down and when I drained it, the 10w40 came out pretty sparkly. It really looked like I had dumped glitter in it. Put 5w30 back in and it sounded totally normal. What gives? I keep reading about people running much thicker oil in these engines without issue. Was mine just that peculiar? Thoughts?

It certainly wouldn't cause any problem in a healthy engine, but I guess in a failing engine, there is a possibility that 10W-40 didn't produce enough oil flow. I don't know how cold it was in Utah at that time. It could also be some other mishap (bad oil filter, insufficient oil, etc.). You may also have heard some other noise coming from a part that is unrelated to oil. Sparkling metal flakes in the oil could also be leftover from the previous oil.

 

[jim302]

I ran Castrol GTX High Mileage 10w-40 on an '89 Crown Vic without any problems. In fact it actually addressed a few minor leaks. Those were some very reliable engines and they were not picky on oil. I don't remember exactly what the owner's manual said, but I seem to recall it showing a very wide range of acceptable viscosity grades, especially in milder climates. Seems like your issue would have most likely been caused by some other factor, such as some contamination getting in during the oil change.

 

[hpb]

Originally Posted By: SilverFusion2010
Originally Posted By: hpb
It definitely wasn't the "thick" oil that caused it. I used to service F150 ambulances in the 90's, running both the injected 5.0 and 5.8, they all ran on 25w60 (not a typo) with no problems whatsoever...


Is that what was spec or was it a fleet oil thing. That's really thick. I can see that they get pushed hard but even most racing oils stop at 50 weight


No it wasn't the spec, but it's what we were instructed to put in them. I agree, it was a very thick oil! Our spare parts department kept 5 litre containers of it in stock, just for the ambulances. I don't know who came up with idea, I was just an apprentice who did as I was told!

The engines had electric heaters installed (Mowarm brand as I recall?), which were plugged in whenever they were at the station, no matter the outside temperature, so they were always warm and ready to go. When on a call out, they were obviously driven hard, and were always left idling while at a job. So realistically, the engines were either running or being kept warm all the time.

I miss the old days of hearing an ambulance with that V8 rumble...our ambulances these days are diesel Mercedes Benz Sprinters...