My new-to-me 240 seems to run pretty smooth although a bit anemic on acceleration. It also seems a little gutless to me, even for a 240. But in all fairness, I usually drive a 2012 Tundra with a 5.7 v8. So maybe my expectations are a bit high. Also, I havent even done a proper tune up on it since I got it other than a fresh set of plugs. Im thinking of upgrading it to a 300 anyway and didnt want to spend money tuning up the 240 until I decide it's going to hang in there for a while. Not sure what the compression should be but today I got readings from 125-140 which sounds about right to me. What should I be getting for compression readings?

I cut open the oil filter when I did an oil change and found almost zero metal in it. Im actually surprised I didnt see anything.

My biggest concern on the engine is that it indicates some pretty low oil pressure readings. The orig owner tells me it's always showed low OP and he tended to just ignore it. Im still trying to find a gauge so I can get a direct read from the block to find out if it's an indication problem or actual low pressure. After doing an oil change to a good quality Castrol 10w30, I get the following:

First few minutes after start up, the pressure runs at almost 80psi...even at idle. Then when the engine warms up, it drops to like 5 psi at idle and indicates about 10 psi at 2000 rpm.

Other than that, so far an oil leak at the rear/bell housing is the biggest gripe I have. Any suggestions on the oil pressure indication would be appreciated. Ive read what I can find on the subject and it does sound like these trucks had a pretty cheezy OP indiction system. So Im hoping to find out it's actually got pressure when I get a gauge on the block.

 

So, I finally got my hands on a direct reading OP gauge today and sure enough, the old stock OP system is not accurate at all. The actual pressure's I got from the tester (after a good warm up on the engine) were 14 psi at idle and 25-30 at 2000 rpm. I know that's probably not an ideal range and likely indicates a tired old engine. But Ive heard some people say that's adequate for the straight sixes.

So what do you guys say is a normal range for one of these engines? And at what point would you tear into it and start trying to increase the pressure?

Realistically, it's probably nearly time for a rebuild or replace. In fact, Im hoping to build up a 300 to swap into it but that could be a while.

 

Comparing the anemic 240 to the Tundra's DOHC 32 valve 5.7L FI V8 is like comparing a yard switcher engine (2-2) to a Big Boy (4-8-8-4).

Oil pressure dropping off dramatically when the engine warms up...it's time for a rebuild, the main and rod bearings have had it.

 

+2 with Bill, it's close to time to rebuild but not stop in the middle of the road shouting OMG. Stay with your plan on finding and rebuilding a 300 to go in it. It very well can run another 3-5 years in the condition that it is in now.


John