# Lower radiator hose stays cool.



## jrc2905 (Apr 24, 2005)

My 2000 Altima has a problem. The motor is rebuilt with 5000 miles on it. When I took it for its first test ride it overheated because I had the thermostat in backwards, duh.
Put a new one on the right way. Yesterday I noticed the engine was making a lot of noise, that sounded like the valve train. I think the engine is getting too hot, I ran the engine with the thermostat out and I have good coolant flow. Installed a new thermostat and took it for a test drive. The lower radiator hose never gets warm, I did double check to make sure I bled the cooling system. Every time I open the bleed I have to clean the hole with a small pick to get coolant flow. I plan to pull the thermostat assembly from the head tomorrow and see what the head connection looks like. The car has always had excellent heat right away and now I am thinking it may be related.


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## Mishimoto (Jun 27, 2012)

jrc2905 said:


> My 2000 Altima has a problem. The motor is rebuilt with 5000 miles on it. When I took it for its first test ride it overheated because I had the thermostat in backwards, duh.
> Put a new one on the right way. Yesterday I noticed the engine was making a lot of noise, that sounded like the valve train. I think the engine is getting too hot, I ran the engine with the thermostat out and I have good coolant flow. Installed a new thermostat and took it for a test drive. The lower radiator hose never gets warm, I did double check to make sure I bled the cooling system. Every time I open the bleed I have to clean the hole with a small pick to get coolant flow. I plan to pull the thermostat assembly from the head tomorrow and see what the head connection looks like. The car has always had excellent heat right away and now I am thinking it may be related.


Interesting. This could also be some form of blockage in the coolign system. It would be wise to pull the thermostat and test it. While doing so see if you can flush the coolant system a few times. 

I wonder if the valvetrain noise is related or not, check your oil level as well. 

Let me know what you find.


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## jrc2905 (Apr 24, 2005)

I hope you are right, I have compression of 180 185 on the cylinders. I bought and used the Block Tester chemical and it turned green not the yellow color to indicated a head gasket leak. I also am waiting on a leak down kit I ordered.
Today I replaced the cat converter because of a bad cat code I have been having. 
While replacing the cat I could see moisture at the bottom of the radiator and when I started the car with out the cooling fans on it I could see a small amount of mist coming off the radiator. I replaced the radiator with a good one that I have off a parts car. I also installed an upgraded thermostat instead of the cheap one. I ran the car and after the initial purge of air from the bleeder and coolant it seems to run with no air in the coolant and I now have some heat on the lower radiator hose. I also adjusted the distributor just a hair and it made engine sound better. I am hoping what I was hearing was a combination of excess heat and air bound coolant in the head. I will test drive it today and post the results.
I did read that some people said it was normal to have a cool lower hose bit that would mean cool water going directly in to the head when the thermostat opens and that can not be right.
Thanks for the info I will post my results. I now have four 2000 Altimas and need to know how to fix one so I will know what the problem is if it comes up again.


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## Mishimoto (Jun 27, 2012)

jrc2905 said:


> I hope you are right, I have compression of 180 185 on the cylinders. I bought and used the Block Tester chemical and it turned green not the yellow color to indicated a head gasket leak. I also am waiting on a leak down kit I ordered.
> Today I replaced the cat converter because of a bad cat code I have been having.
> While replacing the cat I could see moisture at the bottom of the radiator and when I started the car with out the cooling fans on it I could see a small amount of mist coming off the radiator. I replaced the radiator with a good one that I have off a parts car. I also installed an upgraded thermostat instead of the cheap one. I ran the car and after the initial purge of air from the bleeder and coolant it seems to run with no air in the coolant and I now have some heat on the lower radiator hose. I also adjusted the distributor just a hair and it made engine sound better. I am hoping what I was hearing was a combination of excess heat and air bound coolant in the head. I will test drive it today and post the results.
> I did read that some people said it was normal to have a cool lower hose bit that would mean cool water going directly in to the head when the thermostat opens and that can not be right.
> Thanks for the info I will post my results. I now have four 2000 Altimas and need to know how to fix one so I will know what the problem is if it comes up again.


Good to hear. Looking forward to your road test results.


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## jrc2905 (Apr 24, 2005)

Took it for a test drive, same problem. Sounds fine when first start then starts to sound like a diesel with all the noise when hot, it is so hot I can smell it. Even with the heat off the lower hose stays cool. Temp at the tstat housing is 184f and there is no movement of coolant. When I squeeze the lower radiator tube it is like there is no pressure in it. The engine heat has to be going somewhere. I hope my leak down kit comes soon.


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## Mishimoto (Jun 27, 2012)

jrc2905 said:


> Took it for a test drive, same problem. Sounds fine when first start then starts to sound like a diesel with all the noise when hot, it is so hot I can smell it. Even with the heat off the lower hose stays cool. Temp at the tstat housing is 184f and there is no movement of coolant. When I squeeze the lower radiator tube it is like there is no pressure in it. The engine heat has to be going somewhere. I hope my leak down kit comes soon.


Are you getting any white smoke from the exhaust? When the engine was rebuilt was a new water pump installed?


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## jrc2905 (Apr 24, 2005)

No white smoke.
Everything was new except rods and crank. I took the thermostat out when I did the block test and had good flow going through the engine. In doing my research I found a lot of people who have this problem on their cars but could not find any who resolved the problem. I would like to take the head off now but I am going to wait for my leak down kit so I can try it and see if I can isolate the leak if that is what it is. I kinda have been waiting for this day since I ran it with the thermostat in backwards and overheated the engine.


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## Mishimoto (Jun 27, 2012)

How is the condition of your oil? Does it appear brownish like a milkshake color?


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## jrc2905 (Apr 24, 2005)

My leak down test came back fine in the set range on all cylinders. I am going to have to get a oil pressure tester. I do have a small oil leak where the timing cover oil port meets the block. I am wondering if I could be sucking air into the oil flow at that point and cause a oil flow problem in the head. I did drill a hole in the thermostat so I could see if there was flow and it does look like the coolant is moving. Meanwhile I am going to drain the coolant and do a visual inspection of all the cooling components. I am going to do another leak down test with the air bleeder removed.
I hear what sounds like misfires in the engine when it is running and I listen carefully, not a lot but enough to notice. The only other odd thing about this care is the cabin heat gets up to temp faster than any car I have.


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## rogoman (Dec 16, 2004)

jrc2905 said:


> I also installed an upgraded thermostat instead of the cheap one. I ran the car and after the initial purge of air from the bleeder and coolant  it seems to run with no air in the coolant and I now have some heat on the lower radiator hose. I also adjusted the distributor just a hair and it made engine sound better. I am hoping what I was hearing was a combination of excess heat and air bound coolant in the head. I will test drive it today and post the results.
> I did read that some people said it was normal to have a cool lower hose bit that would mean cool water going directly in to the head when the thermostat opens and that can not be right.


Many folks install aftermarket thermostats and end up with overheating problems. Always use a Nissan OEM thermostat; it will cost more but it will be trouble free. When installing the thermostat, the spring needs to be pointing towards the engine and the 'jiggle valve' or 'steam hole' needs to be in a 12:00 o'clock position.


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## jrc2905 (Apr 24, 2005)

I started with the cheap thermostat and upgrade to the best OEM I could buy. Still a problem. I am going to try to install a oil pressure gauge in the car and see if it is an oil pressure related issue.


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## jrc2905 (Apr 24, 2005)

I bought a cheap install in the car oil gage and once the engine warms up it will not go over 40psi. I ordered a professional one online so I can get a better reading. I have an oil leak at the oring on the timing cover and I am wondering if that is the problem. I really hate taking that timing cover off but I may try a new way I thought off.


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## jdg (Aug 27, 2009)

What kind of gauge? 90 degree sweep or 270 degree sweep?
I don't the 90 degree sweep type for anything other than showing me the difference between 0 and something vs. getting an actual numerical indication of pressure.
40 psi warmed up? Not perfect, but not terrible by any stretch.
How old is the oil? What weight oil? What's the temp outside? What rpm are you taking these readings at?


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## jrc2905 (Apr 24, 2005)

The oil test gage I ordered looks good it has the quick attach and disconnect fittings and a pressure release. The oil is new 5/30 Mobil one and all work is done in a heated garage. I dropped the oil pan and checked the pickup, everything is fine. The one thing that I did find was a small piece of plastic about a quarter of an inch. I am thinking it was left over from when the original timing chain broke, or maybe it is something that is related to my new problem, this engine was completely disassembled and rebuilt. I guess the only thing now is to remove the dreaded timing cover to fix my leak and see what is going on.
What I am going to try in removing the timing cover is to remove all the motor mounts except the transmission mount and instead of lowering the engine to get the cover off, I am going to raise the passenger side of the car to clear the cover. This should change the relationship of the angle as it relates to the timing cover and the frame of the car when they are moved.


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## jrc2905 (Apr 24, 2005)

Well I got the lower timing cover off today. It was a lot of time but I did it a little different this time and it came off no problem. This time I put the right upper motor mount back on after I removed all of the area parts. Then when I was ready to remove the timing cover I put a jack under the crank case assembly and removed the upper mount. When I pulled the cover off I had to lower the jack just a little to clear the frame and it almost fell off.
I am thinking the problem may be that I used the cheap oring gasket for the oil hole that came with the rebuild kit, it slides around and really feels loose compared to the old stock one. It could very well result in a decrease of oil flow and that is the spot where I had an oil leak in the timing cover so I know it was not sealing. I have a new Nissan part to replace it with. Also the little plastic part I found was from one of the new guides and both guides are loose to the touch so I am thing of replacing the with better quality. I will see what happens.


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## Mishimoto (Jun 27, 2012)

jrc2905 said:


> Well I got the lower timing cover off today. It was a lot of time but I did it a little different this time and it came off no problem. This time I put the right upper motor mount back on after I removed all of the area parts. Then when I was ready to remove the timing cover I put a jack under the crank case assembly and removed the upper mount. When I pulled the cover off I had to lower the jack just a little to clear the frame and it almost fell off.
> I am thinking the problem may be that I used the cheap oring gasket for the oil hole that came with the rebuild kit, it slides around and really feels loose compared to the old stock one. It could very well result in a decrease of oil flow and that is the spot where I had an oil leak in the timing cover so I know it was not sealing. I have a new Nissan part to replace it with. Also the little plastic part I found was from one of the new guides and both guides are loose to the touch so I am thing of replacing the with better quality. I will see what happens.



Any updates?


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## jrc2905 (Apr 24, 2005)

Well I have been waiting for a couple of parts, I bought a Nissan lower timing chain tensioner guide and installed it while I had the lower timing cover off.
Got the car back together and running today, something is still not right. When it warms up it still makes a lot of noise in the top end. I also have been noticing a slight misfire that I can hear when I run the engine at a steady high rev, this was there before.
I plan to take it to the guy that does my engine work and did the head so he can listen and give me his opinion. I was not happy with the work on this head, first he did not tell me it was the first Nissan head of this type he worked on, he ground the valves and the adjusted the stem height by grinding the valve stem instead of using shims. He charged me $600 for the work when I could have had a rebuild one delivered for a little over $300. The heads I used before I lapped the valves by hand a never had a problem. I already have the parts so I guess I will pull the head have it checked out and install a head gasket.
If that does not work I can get a tested used engine locally for $550.


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## jrc2905 (Apr 24, 2005)

I got the head off today and the only way I can describe the head gasket is "mush". The entire head gasket is shot. I took some pics but cannot post right now. One of two things happened, when I over heated the engine it cause the failure or it was the cheap head gasket I got with the engine kit on ebay. Ether way I can see the that the entire gasket completely broke down and I am just going to clean the head and block to replace the gasket with new head bolts.


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## jrc2905 (Apr 24, 2005)

I started to reinstall the cylinder head today. I got up to 59 ft lb of torque and the number one head bolt broke. I went to auto zone and showed them that my torque wrench was calibrated and certified in Sept. I also had the tech at the shop test my wrench at 59 and it was right on the money, so they could call to verify if they wanted. Since they had no idea what I was talking about they ordered me new head bolts and a head gasket under warranty and when it comes in I will start over. Head bolts made in china.


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## smj999smj (Jan 1, 2006)

Personally, I would ditch the Chinese head bolts and get them from Nissan.


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## jrc2905 (Apr 24, 2005)

Just an update motor is back together. The headgasket is fixed but now it is making another type of noise. I am almost positive it is the valves. I check the lifter to cam and they are way off for the most part according to the FSM. I ordered the shim install tool and when it gets here I will begin to replace the discs. I did read some where that the shims are no longer made, is that true?


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## jrc2905 (Apr 24, 2005)

Quick update, I replaced the engine with one from a salvage yard. Runs good, lower radiator hose warms up after the engine reaches temp the way it should. I am going to take the other engine apart and check it out. I have some ideas but will wait till I get it apart.


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## Mishimoto (Jun 27, 2012)

jrc2905 said:


> Quick update, I replaced the engine with one from a salvage yard. Runs good, lower radiator hose warms up after the engine reaches temp the way it should. I am going to take the other engine apart and check it out. I have some ideas but will wait till I get it apart.


Wow great to hear you got the car running again. Looking forward to what you find with the old engine.


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## jrc2905 (Apr 24, 2005)

I do not have time right now to do any engine work, I have found that it is easer to find good used engines and swap them out. I also just bought a 96 200sx.


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## kxco111 (Aug 14, 2013)

This could also be some way of obstruction in the coolign program. It would be sensible to take the temperature and analyze it. While doing so see if you can cleanse the coolant program a few times...


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