Results 1 to 26 of 26

Thread: Radiator cooling capacity is dropping

  1. #1
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default Radiator cooling capacity is dropping

    My oem radiator is not cooling enough, especially on the highway when driving above 75 mph for longer than 5 minutes it gets to hot, the needle on the dash goes almost all the way to the right.

    I want to keep the Original radiator instead of an aluminium one, I have found a good radiator shop, but they charge 350 EURO for re-coring ex tax. Would this be worth it ?

    The better aluminium radiators including shipping will be the same price or more, only the cheaper aluminium aftermarket radiators would be a cheaper option right now.

    What would you guys advice ? Or is there anyone here who has a good oem 240z radiator for sale willing to ship overseas ?

    Gr Bart
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  2. #2
    Registered User siteunseen's Avatar
    Member ID
    CZCC-24724
    Join Date
    Jul 2011
    Location
    Alabama
    Posts
    1,967

    Default

    The orange car I recently bought was reading too hot for my comfort zone too. I read a older thread that Carl Beck commented on about putting a newer 280 radiator in 240s, said he started using them when they first came out in the late 70s. I bought one and already had a shroud and fan from a '79 ZX, couldn't get the ZX fan figured out though, the hub is recessed unlike the 240s which is all the way up front. Anyway, Blah blah blah and it cools great. Maybe get one and keep the original for later, that's what I did. Pictures soon.
    http://www.classiczcars.com/forums/p...-radiator.html
    amazon.com has one, Amazon.com: Ready-Rad 0433634 New Radiator: Automotive
    Last edited by siteunseen; 07-17-2014 at 02:39 AM.
    1972 240Z #918 New Sight Orange
    1977 280Z #305 Light Blue Metallic
    1972 240Z #110 Persimmons Red

  3. #3
    Nova Scotia,Canada,Earth Blue's Avatar
    Member ID
    CZCC-7641
    Join Date
    Jan 2005
    Location
    NS
    Posts
    4,085

    Default

    Is the pump working correctly. Sometimes the timing cover erodes behind the pump vanes.
    There is scarcely anything in the world that some man cannot make a little worse, and sell a little more cheaply.
    The person who buys on price alone is this man's lawful prey.


    John Ruskin (1819 - 1900)



    ZCars in Eastern Canada seaport ready for shipment to Europe

    http://ZSportCanada.com


  4. #4
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Yes the pump was replaced last year, everything seemed fine on the inside.
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  5. #5
    Registered User tlorber's Avatar
    Member ID
    CZCC-20299
    Join Date
    Oct 2009
    Location
    Los Angeles
    Age
    54
    Posts
    1,190

    Default

    I would first yank the thermostat, and see if you have the same results. Then check if your radiator needs to be rodded out. If you are saying that it worked at some point, that something has changed within the system. A full shroud will help at idle, but at 75 mph you should be moving enough air to cool adequately.
    Tlorber
    '73 240 +/- done
    '73 240 survivor
    '69 SRL 311
    '54 GMC Going onto S10 frame w/LS motor
    '99 Lexus GS Driver

  6. #6
    Low Budget/High Value
    Member ID
    CZCC-20342
    Join Date
    Oct 2009
    Location
    Washington County, OR
    Posts
    3,629

    Default

    Don't forget head gasket and bad gauge as potential causes. Stuck thermostat is a good possibility. If you've been using modern antifreeze formulations with clean water it would be odd for the radiator to get fouled.
    Attached Images Attached Images  
    1976 280Z, with some minor modifications

  7. #7
    Registered User EuroDat's Avatar
    Member ID
    CZCC-26512
    Join Date
    Feb 2012
    Location
    The Netherlands
    Posts
    1,420

    Default

    Hi Bart,

    A simple test to check if its a blocked radiator is to drive it and when it gets hot again open the heater fully and fan at maximum. You should see the temperature drop suddenly and remain a little lower. Thats the extra cooling capacity in the heater.

    Other checks would be to lossen the belt and check the pump turns freely. Check belt tension.

    Another check is to drain some fluid from the radiator enough to expose the tubes. Check how many appear blocked. If more than a third appear blocked, you're not going to have enough capacity in the weather conditons we are now having here lately.

    Some old shops will pressure test your radiator and if it appears ok, they can remove the bottom tank and clean the core. I have done it with a friend on his 1971 ford capri radiator. He used it for 6 years without problems and that was in 40degC summers.

    Good luck
    Chas
    Chas
    5/77 280Z HLS30 403100 with some modifications
    Original colour: 305 Light Blue. The PO changed it to Red

  8. #8
    Registered User siteunseen's Avatar
    Member ID
    CZCC-24724
    Join Date
    Jul 2011
    Location
    Alabama
    Posts
    1,967

    Default

    How free spinning is your fan clutch? Too easy isn't good.
    1972 240Z #918 New Sight Orange
    1977 280Z #305 Light Blue Metallic
    1972 240Z #110 Persimmons Red

  9. #9
    Registered User
    Member ID
    CZCC-7812
    Join Date
    Jan 2005
    Location
    Atlanta, GA
    Age
    53
    Posts
    120

    Default

    I was chasing a "running too hot" problem with my dad's 78 280z. Since we were getting it running again after sitting for several years, I was willing to replace multiple parts while chasing the problem. I replaced thermostat, water pump, fan clutch, and radiator cap. Still, the car ran hot, though not quite as hot as what you described. My dad's car is very original with low miles so I wanted to try and save the radiator. the fins were all straight and visual inspection when looking into the top tank showed nothing obvious. Here is what I did that solved his problem.

    I pulled the radiator. I plugged all hose holes except the cap. I filled the radiator with muriatic acid and let it sit full for 45 minutes. At 45 minutes, I emptied the acid into a bucket and rinsed the radiator for several minutes with water. I filtered the muriatic acid using a towel stretched over another bucket and re-used the acid to repeat the above process three more times.

    Next, I re-installed the radiator, filled with 50/50 anti-freeze and water. His car no longer runs hot, even on 95 degree days in traffic.

    Not saying this is your problem but if you have access to muriatic acid it is something you might consider trying. If you do try this, use gloves, wear sleeves, wear eye protection, don't pour water into a big bucket of acid (acid into water is fine), etc.

  10. #10
    Registered User Stanley's Avatar
    Member ID
    CZCC-24191
    Join Date
    Apr 2011
    Location
    Redondo beach
    Posts
    641

    Default

    If you warm it up with the cap off and see a good flow of coolant when the thermostat opens, you can rule out thermostat, water pump and radiator blockage.

    Tried flushing it? I flushed the old brass one and plenty grit etc. came out of radiator and engine. Finally dumped it though.

    I like the Champion Aluminum 3-row from MSA, not too expensive, looks good, and keeps it cool on the road. Plus it weighs a lot less, which affects shipping charge.
    Last edited by Stanley; 07-17-2014 at 10:16 PM.

  11. #11
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    @ jonathan: my dad said about the same thing yesterday, flush the radiator with acid.

    @ Stanley: I will have a look

    @ Zed head: the oil pressure reads ok.

    @ Chas: going to check the radiator today

    Thermostat was changed last year, but it could be. I'm going to check a few things today.

    Yesterday was a hot day around 28c, and on idle the needle basically got all the way into the red, only when driving on the highway it got a bit cooler, but still very hot like a little over 3/4. When the engine is running idle, I can feel the fan sucking the air when I hold my hand in front of the radiator, I assume the fan is working properly ? My first thought would be radiator, because simply it hasn't been replaced either flushed so far..
    Last edited by bartsscooterservice; 07-18-2014 at 12:48 AM.
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  12. #12
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Quote Originally Posted by tlorber View Post
    I would first yank the thermostat, and see if you have the same results. Then check if your radiator needs to be rodded out. If you are saying that it worked at some point, that something has changed within the system. A full shroud will help at idle, but at 75 mph you should be moving enough air to cool adequately.
    Yeah.. it does cool best so far when driving at higher speeds, to me that looks like a radiator problem. I'm going to try to flush it out..see what it does.
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  13. #13
    Registered User
    Member ID
    CZCC-7812
    Join Date
    Jan 2005
    Location
    Atlanta, GA
    Age
    53
    Posts
    120

    Default

    I just want to be clear that what worked for me was to remove the radiator and use acid. Don't pour acid into your system (radiator installed, car running, etc) like you might with a radiator flush product. You don't want acid touching the rest of your system- just the radiator.

  14. #14
    Registered User EuroDat's Avatar
    Member ID
    CZCC-26512
    Join Date
    Feb 2012
    Location
    The Netherlands
    Posts
    1,420

    Default

    You can also try reverse flushing by using your garden hose and a compressed air pistol to reverse flush it.
    Lay the radiator flat on the ground or a little tilted towards the top with the outlets facing upwards.
    Fit the garden hose and the air pistol into the bottom outlet and seal it as best you can with a rag or something like that.
    Fill it with water until it flow out the top and give it bursts of air. That can dislodge a far bit of crape out the core.

    Oh prepare to get nice and wet. A good weekeind to do it

    The core can get blocked when poeple used stop leak to fix a leak somewhere in the system. I can remember a product called Bars Stop Leak. It had little pellets in it that could cause partial blokkages in the core.

    Chas
    Chas
    5/77 280Z HLS30 403100 with some modifications
    Original colour: 305 Light Blue. The PO changed it to Red

  15. #15
    Registered User siteunseen's Avatar
    Member ID
    CZCC-24724
    Join Date
    Jul 2011
    Location
    Alabama
    Posts
    1,967

    Default

    My Dad would dump a can of black pepper flakes in his work truck and it worked, temporarily. So save the flushings for a BLT.
    1972 240Z #918 New Sight Orange
    1977 280Z #305 Light Blue Metallic
    1972 240Z #110 Persimmons Red

  16. #16
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Okay..

    Yesterday up on opening the radiator cap, I noticed the coolant level to low in the radiator, some must have evaporated ?

    I did a simple thing first, I went to the local auto parts store and got a can of Wyns coolant system flush. Followed the instructions and flushed it, then filled it with new coolant.

    I took it for a drive this morning it was allready 30c. The temp meter stayed a fair bit lower, let's say between 1/2 and 3/4. Will take it for a drive into Germany this afternoon, see what it will do..
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  17. #17
    Registered User
    Member ID
    CZCC-7812
    Join Date
    Jan 2005
    Location
    Atlanta, GA
    Age
    53
    Posts
    120

    Default

    Couple of things to think about based on your coolant level post.....

    If your coolant level continues to drop then you either have a leak or you have a blown head gasket.
    Check your oil. Make sure it doesn't look milky. If yes, then you have another indication of a blown head gasket.
    Pay attention to the exhaust color and smell on startup after sitting and when you accelerate. Does the exhaust look white and steamy? Does it smell like anti-freeze? If yes, think head gasket.

  18. #18
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Oil looks good on the dipstick, exhaust does not smoke as far as I can see.

    It does cool a bit more now. At least it does not run so hot anymore, like when I had 2 days ago.

    Where does the temp needle on the dash meter normally stay ? In the middle ?
    Last edited by bartsscooterservice; 07-20-2014 at 05:04 AM.
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  19. #19
    Registered User siteunseen's Avatar
    Member ID
    CZCC-24724
    Join Date
    Jul 2011
    Location
    Alabama
    Posts
    1,967

    Default

    Mine sits on the right leg of "M" in TEMP. That was hot to me but after putting a meat thermometer in my radiator, 176 degrees, it's that particular cars normal. 3 cars with 3 different normals.
    1972 240Z #918 New Sight Orange
    1977 280Z #305 Light Blue Metallic
    1972 240Z #110 Persimmons Red

  20. #20
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Quote Originally Posted by siteunseen View Post
    How free spinning is your fan clutch? Too easy isn't good.
    I think it's fine, there's some resistance in there, it stops quickly when I spin it with my hand.
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  21. #21
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    Quote Originally Posted by siteunseen View Post
    Mine sits on the right leg of "M" in TEMP. That was hot to me but after putting a meat thermometer in my radiator, 176 degrees, it's that particular cars normal. 3 cars with 3 different normals.
    I found this topic, I think'everythings good to go

    http://www.classiczcars.com/forums/e...over-half.html
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  22. #22
    Registered User siteunseen's Avatar
    Member ID
    CZCC-24724
    Join Date
    Jul 2011
    Location
    Alabama
    Posts
    1,967

    Default

    #10 Walter Moore, is the post that eased my mind.

    "This is typical for me.
    Get a meat thermometer. Put it in the top of the radiator. Start the car and let it idle until it gets full up to temperature. Check the temperature of the actual radiator fluid.

    You will feel better. Trust me."
    1972 240Z #918 New Sight Orange
    1977 280Z #305 Light Blue Metallic
    1972 240Z #110 Persimmons Red

  23. #23
    Registered User tlorber's Avatar
    Member ID
    CZCC-20299
    Join Date
    Oct 2009
    Location
    Los Angeles
    Age
    54
    Posts
    1,190

    Default

    As far as losing coolant, you might want to get yourself an OEM overflow tank:

    Click image for larger version. 

Name:	Tank6.jpg 
Views:	13 
Size:	134.0 KB 
ID:	72902Click image for larger version. 

Name:	Tank2.jpg 
Views:	12 
Size:	151.8 KB 
ID:	72901
    Tlorber
    '73 240 +/- done
    '73 240 survivor
    '69 SRL 311
    '54 GMC Going onto S10 frame w/LS motor
    '99 Lexus GS Driver

  24. #24
    Low Budget/High Value
    Member ID
    CZCC-20342
    Join Date
    Oct 2009
    Location
    Washington County, OR
    Posts
    3,629

    Default

    Pretty sure that Nissan knew the gauges aren't very accurate. That's why the "red zone" is just a tiny sliver at the very upper end of the range and the Owner's Manual describes essentially the whole sweep as normal.

    We should all probably have a better aftermarket gauge somewhere in the car, considering the damage overheating causes.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	No worries.PNG 
Views:	6 
Size:	101.0 KB 
ID:	72903  
    1976 280Z, with some minor modifications

  25. #25
    It's awesome bartsscooterservice's Avatar
    Member ID
    CZCC-28929
    Join Date
    Jan 2013
    Location
    Gendt, The Netherlands
    Age
    33
    Posts
    857

    Default

    It that case it seems normal and there's nothing to worry about ?
    HLS30 32581, 5/71 Matching numbers

    Jay Leno : You know one week after the Americans have walked on the moon, the Japanese introduced this sports car, and…if you’re a car guy pretty equal. I mean walking on the moon was pretty good, but how many times you’d gonna walk on the moon? But here was an affordable sports car that had real performance and looked like it cost a lot more than it did.

  26. #26
    Registered User Stanley's Avatar
    Member ID
    CZCC-24191
    Join Date
    Apr 2011
    Location
    Redondo beach
    Posts
    641

    Default

    Since the coolant level was low, maybe check the radiator and all hose connections carefully for leaks. After a few weeks even a tiny leak will bring the coolant level down enough to overheat the engine. Also use coolant recover radiator cap and overflow bottle, Sapporo or otherwise. They also have a one-liter beer can for extreme conditions such as the desert.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Dropping 83 ZX Motor Into My 77 Z
    By Captain Obvious in forum Engine and Drivetrain (280ZX)
    Replies: 16
    Last Post: 09-02-2013, 10:35 AM
  2. oil capacity
    By nathan 240k in forum Open 240K Discussion
    Replies: 2
    Last Post: 03-18-2013, 03:36 AM
  3. Oil Capacity
    By kjphilippona in forum Engine and Drivetrain (S30)
    Replies: 6
    Last Post: 07-29-2011, 05:20 PM
  4. Radiator coolant and cooling system filters
    By V8-240Z in forum Engine and Drivetrain (S30)
    Replies: 5
    Last Post: 02-20-2008, 01:14 AM
  5. gas capacity
    By hf240z in forum Parts Swapping (S30)
    Replies: 2
    Last Post: 04-25-2002, 10:56 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •