Hello all,

Misspellings are intentional, I hate those damn hover-links.

I have a 2001 Ram with the 318. Water-pmup went out on it and it got really hot trying to baby it back to the house. I am not much of a mechanic, but I am pretty sure that the water pump went out on it. It didn't have any water in it by the time I got it home, and the oil looked just fine. It has been sitting for a few months now and the battery has seemed to have taken a crap on me as well. I found this out by taking in the alternator and the battery for testing. Alternator passed, battery did not. So before I bought a battery and put it in, or started on the water pump, the auto-perts guy loaned me a compression kit. I took the following readings:

Facing the front of the engine, from front to back.

Left side:

132
160
142
148

Right side:

140
78 (103 when I put a little oil in the cylinder)
125
97

I am wondering if I should waste my time with the water pump, of if I have a ruined motor?

Thanks for any helpfull ideas on this.

 

Your numbers are WAY out of spec. You have two cylinders on the right side that are basically dead. The rest are way far apart. (also out of spec...) If the other cylinders don't come up with a bit of oil in the cylinders, you *might* be able to get away with just replacing the heads. (I say "replace" because the stock heads simply are not worth wasting any money on, not even to have them checked.) There are better heads available online for around 600 bucks for a pair of fully assembled, NEW heads, with thicker deck castings. (a lot less prone to cracking.)

I would be REAL tempted to run a cylinder leakdown test on it, and see if most of your compression leaks past the valves. If so, replace the heads as well. The bottom end on these motors is generally pretty stout.

 

Thanks for the feedback, HeyYou! I already had the water pump and started digging into it already. I have the whole thing torn apart, so, I might as well put the water pump on and see if it can at least get me by for a while.

 

I recently took a compression test on my 1995 Ram 1500 ( 377,000 miles ) and had most cylinders showing 175psi- 180psi, I had #5 @130psi dry and 160 with a tablespoon or so of oil squirted in the cylinder. #1 and #4 were 165 and came up 10 lbs with oil.
When doing this test I let the engine turn over 4-5 times to reach these readings with the 2nd rotation showing 150 psi and increasing with each turnover, i did this with all sparkplugs removed and throttle plate wide open, was this the correct method?

Though there are a bizzilion miles on this truck it idles and runs fine but recently after replacing my water pump which turned into a plenum repair with an aluminum replacement cover ( I traced my steel cover onto some stock 1/4" aluminum plate ) and a heater core replaced as well due to leaking on passenger floor my truck is wanting to overheat. I've tried burping the system, installed flush kit to force water through the system, jacked up the passenger side while burping. I haven't let it get too hot but it went passed 200 a couple of times while testing my repair results, I'm stumped on what could be causing my overheating problem, actualyl thought maybe the pump was spinning backwards but have triple checked the belt routing... I drilled 2 small holes in the thermostat to allow water and air to pass as was sugessted elsewhere on this site, seems to still wants to get hot, I havent tried removing the thermostat completley cause I've never had to do this to cure an overheat before in any vehicle.

My radiator was replaced 3 years ago after the plastic side started leaking and I always run antifreeze / water mixture roughly 50/50 ratio. Before I replaced the waterpump I had added some stop leak to try to stop a trickle leak I had coming from my timing cover, I've rinsed my radiator from bottom and out the top and top to out the bottom, water seems to pass through fine.

I had to leave my truck sit for about a year with my intake off after getting bit by a Pygmy Rattlesnake and couldn't get it back together until recently, this wasn't happening before my plenum and heater core replacement. I'm going to relace my belt tentioner cause it is over due but don't think it's slipping. I'm stumped, any ideas? I need to rebuild the engine sometime cause I know the rings at the very least are worn down but this overheat has me beat right now, with all the miles on this truck it has always had cold AC and a smooth running engine ( transmission another story , 2 rebuilds...) I've always been a decent mechanic with help from you folks here on Dodge Forum and my Haynes book to assist but I'm lost on this one, thanks for any help, sorry to be long winded and hijacking the op's thread but the compression test is related to original post... Thank you all --

 

Stock thermostat is 195 degrees, and the temp gauges aren't the most accurate things in the world. Seeing your temp gauge nudge up over 200 is actually normal. Now, if it continues to rise past that, you may have a problem... but, if it sits right around the 200 mark, that is perfectly fine.

How hot is it getting?

 

What a pain in the a$$ job that was. However, I got the water pump, thermostat, and new hoses all installed. I had to buy a new battery, because it was at my previous mechanic's house for three months without being touched. But it's running just a good now as it was prior to having the water system issues. I'll run it until the wheels fall off. Thanks for the feedback.

 

Thanks for the reply, I've owned this truck for 15 years and it has always ran around the 200 mark but after the plenum repair it came up to 225 before I shut it down. I then took the thermostat out and drilled the 2 small holes to let some water pass before 195 to purge any air that may be in the system, the temp is still wanting to go past 200 but not as fast as before.All gaskets and thermostat itself are new, with the radiator cap off I can give it some throttle and the coolant goes down a bit and does not try to overflow or spit water out like a blown headgasket might...

I hooked my vacuum gauge to a port below the throttle plate and the needle is steady in the green zone showing good vacuum. one thing I have noticed is that the radiator doesn't seem to be under pressure when I remove the cap after releasing the lever on the cap.

I know I can leave a deposit and borrow a radiator pressure tester or a leakdown test kit, which would be the best test to do to isolate the problem?

There is no water in my oil nor oil in my water that I can see and no leaks externally. Thanks for the help and sorry for the late reply, I'll keep an eye on the thread today... Thanks again!

 

After doing the plenum, etc, on my truck, first startup the engine got to around 240 before it actually opened the thermostat, and started circulating. Afterwards, it would never go much above 210 or so. Replaced the radiator, as it was leaking..... and now if barely ever edges over 200.

 

The fact that the radiator isn't under pressure at 200 degrees concerns me, it should release some steam as soon as I release the lever on the cap but it doesn't. I have removed the upper hose from the top of the radiator and confirmed that there is water moving through it though not as strong of a flow as I would expect but that may have been the thermostat not fully open. I'm gonna run it around the block awhile today and see if there is any change, maybe borrow the radiator pressure tester... Thanks for your reply, 200 degrees is what I'm hoping to achive...

 

Yeah, at operating temp, there SHOULD be pressure on the system. If there isn't, you *should* see evidence of a leak somewhere...... Of course, these trucks have some interesting places to spring leaks..... the freeze plugs on the back of the motor, and the ones behind the motor mounts are fun to find.