Engine runs REALLY hot since new water pump

[PackMan22]

Just swapped the waterpump on my 1990 AT Bronco 5.8L. Now the engine runs really hot, I can't make it across town without the engine starting to overheat. Took it out again today and same thing, went around the block a few times just to get it warmed up and it is like there is no coolant going through the engine at all. I have a slight coolant leak, but the engine shouldn't overheat just because of a small coolant leak, right?

I followed an instructional while putting the waterpump in, and have rechecked it a few times, everything seems to be right as far as the installation goes. Is it possible to tighten the waterpump too much? I was sure to tighten it pretty well because I wanted to make sure the gaskets (all of them) sealed.

If anyone can help, it would be really appreciated.

Thanks.

 

[69bronc347]

where did you get the waterpump from, did you let the engine run without the rad cap on to the burp all the air out of the block, if the thermostat does not open before you put the cap on you will air lock the block annd it will over heat, check the coolant level to make sure it is full, then burp the system,its possible that the thermostat is stuck, but it would be quite the quincadense that it would go out exactly when you did the waterpump, i do believe there is a regular flow pump and a reverse flow pump, but not quite sure on that

 

[Seabronc]

where did you get the waterpump from, did you let the engine run without the rad cap on to the burp all the air out of the block, if the thermostat does not open before you put the cap on you will air lock the block annd it will over heat, check the coolant level to make sure it is full, then burp the system,its possible that the thermostat is stuck, but it would be quite the quincadense that it would go out exactly when you did the waterpump, i do believe there is a regular flow pump and a reverse flow pump, but not quite sure on that

That regular flow and reverse flow business sticks in the back of my mind also. The only problem is I can't remember what the details are. Perhaps Miesk5 has a link to the information.

>-

 

[PackMan22]

I bought the waterpump from an autoparts store Napa or Autozone or something, can't remember exactly which one. And I've heard of the reverse flow thing before and I think it is based on year. I guess it is possible that the employee gave me the wrong one, but I would have to break it down and check to see if it matches the old pump (which I fortunately kept for no particular reason). And I do have all of the gaskets needed to take it apart and check, and a 3 day weekend coming up.

I guess I really have no excuse (other than laziness, my personal favorite) not to pull the pump off and make sure I have the right one. I guess I could try burping the system first to see if that helps first. Thanks for the help so far, keep up the suggestions.

 

[AdamDude04]

Yeah I'd say a faulty pump. Or quite possible, faulty fan clutch..but in the same, boat, hard to say that failed same time you changed your pump..

 

[bobstrat]

was your water pump obviously faulty?

did you change the thermostat as well?

 

[PackMan22]

Bob,

No and no. Should I have changed the thermostat as well? Is it common for the thermo to go out or have problems when the waterpump is swapped, or are you suggesting that this sounds like a thermostat issue? Changing the thermostat looks like an easy enough process.

Thanks for all your help so far guys, I really appreciate it.

 

[Elmo]

If water pump was not faulty before you swaped it then Why did you swap it. And from where is this leak that you said you still have? I would remove rad cap start engine turn the heater on and keep coolant level with in sight as the engine warms up. As the coolant and air heats up they will expand therefore causing some of the coolant to be forced out so keep an eye on the level. It will rise and fall when it falls out of sight slowly add coolant till it is in sight again. Continue this till engine is at full operating temp and coolant level no longer drops out of sight. if during this 15 -20 min process it runs hot you either got the wrong pump or got lucky enuf to have the thermostat lockup on you. the parts store that sold you the pump should be able to look it up again and verify that they gave you the correct pump.

 

[PackMan22]

If water pump was not faulty before you swaped it then Why did you swap it. And from where is this leak that you said you still have? I would remove rad cap start engine turn the heater on and keep coolant level with in sight as the engine warms up. As the coolant and air heats up they will expand therefore causing some of the coolant to be forced out so keep an eye on the level. It will rise and fall when it falls out of sight slowly add coolant till it is in sight again. Continue this till engine is at full operating temp and coolant level no longer drops out of sight. if during this 15 -20 min process it runs hot you either got the wrong pump or got lucky enuf to have the thermostat lockup on you. the parts store that sold you the pump should be able to look it up again and verify that they gave you the correct pump.

I guess I misunderstood the original question. The original waterpump was leaking from the weephole on the bottom of the pump, which I heard is a sign that it is going out, and I thought it was the source of my coolant leak. I thought he was asking if the new waterpump was clearly faulty, which I didn't really inspect it since it was new in the box. After replacing my waterpump it looks like I also have a leak coming from behind the water pump, I think it is coming from the lower intake manifold, I hear the bolts in this get corroded and often leak (my next project). But a slight coolant leak doesn't matter much if you can't go more than a few blocks without overheating.

 

[bobstrat]

I guess I misunderstood the original question. The original waterpump was leaking from the weephole on the bottom of the pump, which I heard is a sign that it is going out, and I thought it was the source of my coolant leak. I thought he was asking if the new waterpump was clearly faulty, which I didn't really inspect it since it was new in the box. After replacing my waterpump it looks like I also have a leak coming from behind the water pump, I think it is coming from the lower intake manifold, I hear the bolts in this get corroded and often leak (my next project). But a slight coolant leak doesn't matter much if you can't go more than a few blocks without overheating.

i was referring to the original water pump, and it sounds as though it was faulty. i normally change the t-stat when changing the water pump, but if you didn't, that could be the problem now. you may also have a faulty radiator. check for cold spots on the rad when the truck is hot. CAREFULLY, burnt fingers ****.

 

[Elmo]

If sitting still can you run the engine for 20-30 mins without it running hot ?

So original pump was leaking ( faulty/bad) you replaced it and still have a slight leak. Would the engine run hot if driven around the block before you changed the pump ? If so this would lead me to suspect the thermostat or maybe head gasket. So it ran hot the first time you ran the engine after installing the pump, once it cooled down did you recheck the coolant level and refill, doing this could possibly have gotten some of the air out unless it puked all the coolant out when it overheated,this ofcourse would put you back at square 1.

Now about this leak, does it leak when engine is off and cold, and get worse when the engine heats up,or does it only leak once the engine gets warmed up and system is pressurized ? Is it possible, due to this leak you still have, that during your trip around the block all the coolant leaked out therefore resulting in the engine overheating ? Dont take me the wrong way I am in no way tring to insult your intelligence or mechanical abilities there just are lots of little indicators that can point out a problem and some times what I may see as inconsequential someone else will see as a flashing neon sign saying "here i am".

 

[PackMan22]

Thanks to everyone who helped me, but I finally figured out the problem.

I got a lot of ideas; bad water pump, intake bolts, thermostat, timing cover, etc. I'm no mechanic, and don't have the knowledge or time to really diagnose these kinds of problems, but as far as I could tell, everything pointed to the waterpump being bad (or the wrong pump). So I finally broke down and took it in. It turned out to be the thermostat was stuck (one of the only things I think I could have fixed myself) which was causing the overheat. But the leak is coming from the timing chain gasket, the seal was broken when I took off the old waterpump, hence the continued leaking after the swap (the old water pump was still no good).

So I still have the slight coolant leak (that I will fix eventually) and a slight oil leak (that I will fix eventually) but she runs smoothly without overheating anymore. Thanks again to everyone who threw in their 2 cents, what is obvious to you guys never occurs to us and your advice is really appreciated by us novices.