Do I believe my mechanic?
 

My Supra was way low on oil and when I took it into the shop I was told that they believe I had "at least a couple" of rods knocking in my engine. They say "believe" because the engine will have to be taken apart to know for sure. They said when it was brought into the shop one of the mechanics asked if it had a diesel in it the car was so noisy. I drive 550+ miles per week and that was at least six weeks ago. Since then, my engine has not died, in spite of the fact that I drive the car in excess of 80 mph every day. As long as I keep oil in it the engine sounds fine but if it gets low I start to hear the "diesel" clicking sounds again. My mpg has been about the same; while I don't have exact numbers I am not having to fill up any more frequently than before.

The shop I take it to is very highly regarded; in fact, the local Toyota dealership sends work over there on occasion. That said, I really wonder if the noise could possibly be coming from something else related to the cams/valves. I know these guys know their business but they don't see very many Supras or Cressidas with this engine come in because there aren't that many where I live. I watch for both of these types of cars and I know of only two Cressidas and another Mk IV.

Can anyone add any input on this? I was planning on driving it until it died but when I took it to Carmax recently to get an offer on buying it they told me engine sounded good and ran well. If it could actually be something else I'd just as soon keep this car.

heavier oil, and STP
 

Any experienced tech can differentiate (?) the sounds in an engine.
Rod knock, valve lifter, crank bearing.

When your engine runs low on oil, then you are harming ALL the parts. Rod knock will likely show up.

Make sure you use 4 qts 20w-50 oil, and.....
1 bottle of Lucas oil treatment,
OR
2 bottles of STP oil treatment, at each oil change.

Trust me (just look at my credentials), this is the only way you will "prolong" the engine life, and prevent further damage.

If the engine is pretty quiet with this oil and treatment, keep it full, and drive it until you can make needed oil leak repairs, or new engine.

Wow that bites.

On most cars you're safe to check the oil and other fluids upon every fill up.

With a supra. Well..., I check mine daily when it's running.

To avoid the afore stated problems.

Lucas would have my vote over the stp.

I keep some of both. For emergency purposes.

Because you just never know.

Start saving for an engine swap if you love the car.

take it too a few other places, see what they say