Cold lower radiator hose after new thermostat install. Pulled the water pump. How do you know if it is bad??

Ask technical questions or post on problems/issues related to the Kizashi under this topic. Symptoms and pictures of your problem are a good idea.
NOTE: Any car related technical question can be posted here.
Post Reply
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

As it states in the title. I removed the waterpump after replacing 2 thermostats and the water coolant sensor.. Both thermostats are opening at about 185 or so on the kitchen stove with a thermometer. I replaced all the antifreeze and did the burp of the cooling system with the large funnel until all bubbles were gone. Let the car sit and idle in my garage for 30 minutes, then revved the engine to 2200 rpms for 5 minutes or so and the vehicle stayed cool. Plenty of heat through the vents. I drive it to put it under load and it overheats in 5-6 minutes, then the gauge comes down pretty quickly, so I drive it a little more. It gets HOT and stays hot. I let it cool down a little and drive home. Pulled the waterpump and am now inspecting it. The fins move as typical inside the waterpump as I spin the pulley. I was hoping that the spline that holds the fins would've been severed, so I would definitely know it is bad, but it makes an ever so slight noise when I spin it, but certainly not the fried bearing sound. I hate to replace the waterpump and still have the same issue. Car has 85k. No antifreeze in the oil. I took a couple pix of the inside of the waterpump.

User avatar
SAEED_KIZZY
Posts: 230
Joined: Wed Sep 13, 2017 2:31 pm

if I understand you correctly your new thermostat is always closed no matter what temperature your engine have. if so either you install the wrong thermostat or you have air in your system.
I think the thermostat has a bleed valve did you install it correctly?
New Bitmap Image.jpg
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

It's hard to know if it is closed. I just replaced the thermostat and it is still not getting past the thermostat. I definitely installed it correctly with the bleeder at the top. I replaced the water temperature sensor, the thermostat, & the coolant. The thermostat is attached to the water pump, so something is making me think that the waterpump is not letting the water move past it to the thermostat at a reasonable rate of speed. The lower hose should be warm after idling for 30 minutes and raising the rpm's to 2400 for 5 minutes. Definitely getting heat into the car, but it stayed cool until I drove it. It overheated as soon as I put a load on it and drove it a few miles up the street. THEN the gauge moved over to hot, came down about 45 seconds later, then got hot, and the gauge started to approach the red line. Lower hose was still cool. Upper hose was VERY warm
User avatar
SAEED_KIZZY
Posts: 230
Joined: Wed Sep 13, 2017 2:31 pm

if you have heat inside your car your water pump is fine.
you can remove the thermostat and check again.
maybe your radiator is clogged?!
according to the service manual flow of water is from the radiator into the engine through the thermostat so it gets hot water last.
photo_2021-02-19_15-00-34.jpg
old tech
Posts: 298
Joined: Mon Apr 23, 2018 1:51 pm
Location: n/w pennsysvania

At this point, I have questions more than answers. What model yr? (poss block recall 2010) If you smell coolant reserve, does it smell like antifreeze or something bad? ( hydrocarbons ,unburned fuel).Was the reason for the first replacement of thermostat because of overheat ? Has vehicle ever lost a belt mysteriously? Has vehicle ever run low on coolant?
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

Thank you for your response and awesome insight. I sincerely appreciate you taking the time to help.

Now I'm worried. The antifreeze was super clean when I drained it. No rust or scale or anything nasty. It was a clean blue. I can't understand why, but maybe maybe the radiator has an issue. I guess the best way to find out is to close the draincock, and pour water into the upper radiator inlet and see if water comes out of the lower radiator hose?? I just bought a new water pump, and although the old one sounds a little noisy, it should've still worked. I always thought the the water pump fed water to the thermostat, not the other way around. The thermostat was tested in a pot of water that I had a temperature of 180, then 185, then 190, then 200. The original began to open at about 188 and didn't fully open until it reached approx 205 or so. I bought another one and it opens a little earlier.
:facepalm:
SAEED_KIZZY wrote: Sun Feb 21, 2021 3:38 pm if you have heat inside your car your water pump is fine.
you can remove the thermostat and check again.
maybe your radiator is clogged?!
according to the service manual flow of water is from the radiator into the engine through the thermostat so it gets hot water last.
photo_2021-02-19_15-00-34.jpg
Last edited by aerovette99 on Sun Feb 21, 2021 5:55 pm, edited 2 times in total.
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

old tech wrote: Sun Feb 21, 2021 4:34 pm At this point, I have questions more than answers. What model yr? (poss block recall 2010) If you smell coolant reserve, does it smell like antifreeze or something bad? ( hydrocarbons ,unburned fuel).Was the reason for the first replacement of thermostat because of overheat ? Has vehicle ever lost a belt mysteriously? Has vehicle ever run low on coolant?
OK Great. Thanks so much for replying. Here are the answers..
2012
definitely antifreeze. No hydrocarbons. That was my first thought that maybe a head gasket, but definitely smells of antifreeze. Changed oil and no smell of any gas or antifreeze. No extra fluid of any kind in dirty oil.
overheated 2019 summer, so I replaced clean blue antifreeze with blue antifreeze. Was fine until a month ago, when my son said it got hot for a moment (on the gauge, a/c shut off, then it suddenly cooled down, then overheated the more he drove)
Never replaced the belt since we've owned it (bought it with 65k). Purchased an new one to replace when the water pump comes in, hopefully tomorrow.
Never been low on coolant
old tech
Posts: 298
Joined: Mon Apr 23, 2018 1:51 pm
Location: n/w pennsysvania

There isn’t too much to this system. You need an enclosed system that can hold pressure which can be confirmed within ten minutes after running. The hoses become firm to the touch. You need cooling fans that operate and a thermostat that opens and of course a water pump. If you have heat inside the vehicle then your water pump is definitely working, just as SAEED said. My gut tells me that you are dealing with a small head gasket leak allowing just enough compression to leak into the cooling system to interrupt flow of the cooling system. Some engines can deal with a small amount of head gasket leak like this, but this one cannot. This leak is sometimes hard to confirm with smelling, but could be confirmed with an exhaust gas analyzer or possibly some test sticks from the parts store. This kind of leak would cause a very rapid overheat at times while other times seems fine. I imagine you have checked your cooling fan operation. And when the cooling fans are running there should be heat coming off from them as they cycle on and off. If they are running continuously with probably just cold air coming off of them it is usually because the engine computer realizes that there is a malfunction and is turning them on to expel any heat that it has. I guess the good news that I can tell you is that the cylinder head can come off while in the car as I have had to do this a couple of times. Both the block and the head should be checked with a straight edge. The head can be shaved as much as .0020 in, BUT NO MORE. I’m sure the manufacturer will tell you much less for reasons of emissions because compression and cam timing are slightly altered.
As far as water pumps, the OEM is quite expensive around $250 retail. This makes after-market brands look rather enticing, but my experience with them is a used original would be less risk. I had another shop install three after-market pumps on the same car and cause overheating at least twice because of the after-market pump. I can sell you an original brand new Suzuki pump at $150 plus Shipping if you need it. If you are using the after-market water pump, just watch it closely for a while. If the cooling system has been kept clean, there should not be any trouble with the radiator. But rinsing it out while the system is apart is a good idea.
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

With the radiator still in the car, and the hoses removed from the engine and waterpump, I sprayed water into the radiator through where the cap is installed. Water came out of the lower hose very slowly. Slower than I had anticipated. I continued that for about 10 minutes or so.. Then I put the nozzle into the upper radiator hose and water flowed rapidly through the water pump area (water pump is not on the car, as it hasn't been delivered yet). I then put the water nozzle into the upper radiator spout where the upper radiator hose connects and water started flowing faster through the lower radiator hose. Broke of a small chunk of the upper radiator spout but still more than enough to reinstall the upper radiator hose. Crappy brittle plastic. Lastly, I put the spray nozzle back in the radiator through where the cap goes, and it appeared that water was flowing out of the lower hose more rapidly, at least it appeared that way.

Just in case, does anyone have the repair manual pages for head gasket replacement? Removal looks fairly easy, but the timing chain and timing needs to be SPECIFIC or I'll get in trouble. Haven't done a timing chain/belt in 30+ years.

Thanks to everyone that has supplied input and opinions. MUCH appreciated.
aerovette99
Posts: 10
Joined: Sun Nov 29, 2020 2:32 pm

I want to thank EVERYONE that has responded and helped. You all are GREAT.. I completed the waterpump, thermostat & serpentine belt replacement with no issues, and I finally have a toasty lower radiator hose and the car is no longer overheating. No need to pull the engine apart for head gasket (phew) :drive: :D
Post Reply