ThreePointFive Posted May 3, 2008 Share Posted May 3, 2008 Hi all, I replaced the water pump on my 3.5L V8 after it had too much play in it (more on that in a minute). Since replacing the pump the engine heats up a lot quicker and at normal road speeds (30-50) the temp gauge is staying at a steady 3/4 to hot. It used to be almost immovable at dead vertical at these speeds. I tested how hot it would get at lower, higher rev speeds. So I picked a 2 mile long hill which is pretty much 2nd gear all the way. The needle was at the end of the white and almost in the black bit between white and red. Off road, before the change of pump it would be at this kind of temperature and even sometimes into the black (I don't think it ever reached more than just below red). If it is this readily hot, I can't see how it will fair well off road. Is this normal, or should I be checking the water pump? I have used a 50/50 mix of antifreeze and water whereas before it was more like 1/4th antifreeze. Would this have any effect? I think that might be clutching at straws. Fitting the water pump, I had two bolts snap while tightening them up again. I had used loctite gasket replacement stuff as it looked like good stuff as well as the gasket that came with the pump. The problem is, it's glued the pump on pretty much, so I couldn't remove it to extract the snapped bolts. I am wondering if I hadn't used too much loctite and if it is hindering the pump from turning as it could have squeezed itself in to the inside of the housing when the pump was put on. At the moment I am running it with all but these two 11mm bolts in, it isn't leaking at all but I feel it's a bodge. I am not sure how to get the pump off without a hammer, and judging by how easily marked the ali on the old one was, it will mean a new pump. So, the question is, should I be worried, or is this normal? I know it could be the radiator, but it looks fine on both sides, bar a small patch of corrosion on the engine bay side. How hot would a healthy V8 be running at on the road and off it? I am going off roading tomorow so I suppose that will be the test to see if it is going to get any hotter, I can't hthink of any other way to do it. I will have to take it offroad at some point anyway... I know this whole thing is bloody stupid of me, but I really am in need of finding out if there is a problem or not. Quote Link to comment Share on other sites More sharing options...
tacr2man Posted May 3, 2008 Share Posted May 3, 2008 The pump would not be affected by the sealeant as if it was stopoped the belt would squeal and burn. The antifreeze mixture is not relevant, although you should not exceed 50% mix. The temp it should run at will be the same on or off road, as the temp is controlled by the thermostat. The temp is stopped rising too much by the radiator and viscous fan. The normal operation temp range is in the black area. white is to cool and red is getting too hot. So if i read your post correctly it would seem that its operating OK . As long as its not getting into the red, at any time you should be OK HTSH Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted May 3, 2008 Share Posted May 3, 2008 If the temperature has changed since you changed the pump, You changing the pump has the highest likelyhood of causing the change!!! Stopping the pump is one thing, seriously affecting the shape of the inside of the pump body, or flushing sealant round the engine is another, how much sealant did you use? did you let it go off properly before re-filling the system? Is the cooling system bled properly? A new pump shouldn't make the engine run hotter, if anything it should be the opposite. IMHO there's no point looking elsewhere for a fault when you've disturbed the system yourself. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 3, 2008 Author Share Posted May 3, 2008 I must admit a lot more sealant than I wanted to use was put on, as it was the stupidest design of applicator I've ever seen. I tried smearing it around to even it out but I'm not sure how effective that would have been. It was at least 6 hours before the system was refilled, the sealant had definetly set before it was. I took the bottom hose off the radiator to bleed it so I am pretty sure it was fully bled. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 3, 2008 Author Share Posted May 3, 2008 The pump would not be affected by the sealeant as if it was stopoped the belt would squeal and burn. The antifreeze mixture is not relevant, although you should not exceed 50% mix. The temp it should run at will be the same on or off road, as the temp is controlled by the thermostat. The temp is stopped rising too much by the radiator and viscous fan. The normal operation temp range is in the black area. white is to cool and red is getting too hot. So if i read your post correctly it would seem that its operating OK . As long as its not getting into the red, at any time you should be OK HTSH I missed this post! Black is normal? Well then, my car is very rarely at that temp. The pump pulley is rotating with the belt just fine, no noises since I tightened it up. Off road where I'm using low box the average temp is the end of the white, I assumed this was due to the revs being that much higher for little ground speed, and thus less air through the radiator. I think tomorow is the perfect time to see where the temperature stays, and identify if I do indeed have a problem. My only other choice is as luke and I have been discussing, cutting the sealant with a stanley and dismantling the whole lot and trying again. Thing is, as Luke says, the temperature shouldn't have changed if I have replaced the pump, only gone down.... Thanks for your help. Quote Link to comment Share on other sites More sharing options...
sheltie50 Posted May 4, 2008 Share Posted May 4, 2008 Hi, You say that you took the bottom hose of to bleed it, air will be at the top and will stay there until you let it out, try bleeding from the top only, does your heater work if not has a head gasket gone, or is it just airlocked, you could try a new thermostat but I think bleeding air could help, while the engine is cold check the radiator level rather than the expansion tank. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 4, 2008 Author Share Posted May 4, 2008 We checked the rad level, ran it, checked it again, I'm sure it's not airlocked now. It was after that the 'problem' persists. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 4, 2008 Author Share Posted May 4, 2008 I have been out on a play day site and not once did the needle get any further up the scale than the end of the white and it definetly didn't get into the black. On the old pump it would get well into the black at offroad speeds. I still don't understand why it is so quick to warm up now, and it's normal temp is higher, but it's not higher off road so I guess there is no problem with it as it is. Why would its average temp be higher but not go as high as the old one off road? Quote Link to comment Share on other sites More sharing options...
western Posted May 4, 2008 Share Posted May 4, 2008 the increase in anti-freeze mix will allow the engine to run at a slightly higher temp, as you have upped the mix from 33% to 50% it means the water/AF mix will tolerate a higher temp before boiling. Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted May 5, 2008 Share Posted May 5, 2008 Hi 3.5, Are you sure that you dont still have an airlock in the system- the change in running temperature is not a good thing and you are right to be trying to track down the problem. I take it the new pump is not noisy and that there is nothing else symptoms wise? Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 5, 2008 Author Share Posted May 5, 2008 Hi Milemarker, I can't hear anything specifically coming from the water pump, there are a few squeaks and noises from the engine but there always has been. One other thing (I'm probably going to sound very stupid here), I cleaned the end of the fan with the round-spring type thing on the end of it (yep, I knew I would sound stupid). Does this has have something to do with making the viscous coupling on the fan work? It was caked in thick oily mud, so perhaps the fan was being heated up quicker by this mud and working sooner? Probably talking rubbish. Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted May 5, 2008 Share Posted May 5, 2008 One other thing (I'm probably going to sound very stupid here), I cleaned the end of the fan with the round-spring type thing on the end of it (yep, I knew I would sound stupid). Does this has have something to do with making the viscous coupling on the fan work? It was caked in thick oily mud, so perhaps the fan was being heated up quicker by this mud and working sooner? Probably talking rubbish. Yes the spring is to do with the viscous fan working- when the engine is cold you should be able to spin the fan freely (when the engine is not running!), when the engine is hot you should find that the fan is very much harder (if not impossible) to spin with the engine switched off. Basically it is designed such that when the engine is cold, and therefore needs no cooling, the fan is not running at full speed as it is allowed to slip in relation to the pulley driving it. When the engine is hot and needs cooling the fan coupling tightens and the fan then spins at the same speed as the pulley, therefore faster and does the additional cooling. It is possible that in cleaning it you may have damaged the coupling so that it is not running the fan as fast as it used to. You could either look to replace the unit (if it is faulty) or put some electric fans on instead. (Electric fans would be a useful mod in any case as you will release more power OR improve your fuel economy (depending how you drive!) Lots of threads on electric fans- second hand ones from scrap yards are the cheap way to go. Either way you could do with trying to sort out the bolts that hold the water pump on- yes it will be a pain in the arse... I would suggest that clamping the pump up with only couple of the bolts may allow the pump to flex as it is not being held in all the places it was designed to, and may start to leak or indeed die quite quickly- others may advise differently.... Si Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 22, 2008 Author Share Posted May 22, 2008 To continue on from the high temperature (you never know, it might help someone else), it was discovered that my viscous fan is indeed not working. You can spin it freely when the engine is hot. If anyone has one going that works, I'm looking for one! I don't know if it was working prior to the pump renewal, so when I get a replacement I will see how it effects things. I'm amazed how it handles working without one though. I don't want to go the electric fan route for reasons of complexity to fit and I like to keep as much standard as possible, it is just much easier to bolt on a replacement. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 22, 2008 Share Posted May 22, 2008 I wouldn't count an electric fan as complex - an X-Switch, a fuse and a relay. If you want to be able to force the fan on (working hard) or off (wading) then you can add the complexity of a switch. My V8 sits at about 72 degrees all the time, which is the temperature of the stat. Occasionally it gets warm enough to kick the fans on slow speed at ~82 ish. Really it should sit in the middle of the temperature gauge unless working hard. Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted May 22, 2008 Share Posted May 22, 2008 I don't want to go the electric fan route for reasons of complexity to fit and I like to keep as much standard as possible, it is just much easier to bolt on a replacement. Electric fans are really straight forward to fit- it would improve your fuel economy, or give more power depending on how you drive. You would also be able to turn them off in water so you might make it further than you would with the viscous fan throwing water every where in the engine bay. There are lots of threads on here about the type that you can get very cheaply and how to fit them and indeed wire them- if you get stuck then the forum is always here as well! Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 25, 2008 Author Share Posted May 25, 2008 Milemarker, I appreciate there are advantages to an electric fan, but at £30 for a new viscous unit I must say, for something I can just bolt straight on it's very tempting. I have been looking at electric fan installations and to be fair they seem like a good idea, but they also lack of factory-fit quality I like! How do you determine when the viscous unit really is faulty? Should it have no resistance at all after being hot if broken? Matt Neale took a look yesturday and wasn't sure it is faulty, and after being run, if I give the fan a quite hard flick it does a 1/4 turn. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted June 23, 2008 Author Share Posted June 23, 2008 There is still a problem even after I have fitted a new viscous, the viscous itself isn't giving any resistance even at normal running temperatures, it's looser to turn than my broken one was at the same temperature. Is there anything that could be stopping heat getting to the viscous to make it work? Also getting a fluctuation in heat, with it changing quite rapidly. Interested to know of anything that could solve this (I know there are topics on fluctuating heat but not on a new viscous not working as well, could this be related). Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted June 23, 2008 Share Posted June 23, 2008 The problem may be nothing to do with the pump...................... but you might have distrubed something else........... Tell me .............. is your 90 an original V8 ? ...................if not wasit a 2.5 petrol or NA stinkin derv ? , If the original temperature gauge was retained then the 3.5 sender in the inlet manifold is not matched to the gauge...........the temperature gauge will read about 3/4 scale when the engine is at the correct temperature.............. Your original post struck me as if the thermostat was not closing fully but now is ................ there could have been some sh!t jammed in there that you have disturbed by dumping the coolant to replace the pump.................. Ian Quote Link to comment Share on other sites More sharing options...
SteveRK Posted June 23, 2008 Share Posted June 23, 2008 I've never known a viscous fan to lock up solid on a hot stationary engine and ive had countless cars with viscous fans so i would ignore the fan. You can hear the viscous cutting in when the engine is very hot and running by the noise it makes pulling air through. Weaken the anti-freeze strength. Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted June 23, 2008 Author Share Posted June 23, 2008 Ian, it is an original V8. It was in the red at the last drive round day I did so I need to get this sorted before 7 Sisters or I'll be having a rather not fun weekend. I will try anti freeze strength as it was a higher concentrationt than before. Cheers guys. Quote Link to comment Share on other sites More sharing options...
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