Temp up and down after coolant flush

Discussion in 'Street/strip 400/430/455' started by magic marouke, Apr 6, 2019.

  1. magic marouke

    magic marouke Well-Known Member

  2. 1969RIVI

    1969RIVI Well-Known Member

    I have the Champion AE161 in my 69 Riv and it works amazing! Only mod I had to do was the upper rubber insulator mounts. I had to make the inlet side smaller and the fill neck side thicker by using a block of rubber and shaping it with a knife and palm sander.
     
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  3. Electra Bob

    Electra Bob Well-Known Member

    Here's the thread on my radiator, thermostat and clutch fan replacement. This got my temps under control in 100+ ambient temps last summer.

    http://www.v8buick.com/index.php?th...ees-by-spending-and-scraping-knuckles.334678/

    Radiator details:

    https://www.jegs.com/i/Champion-Coo...uw_FtdqUvLhcnLY2Ic1eJ1jSHqB77GchoCW3YQAvD_BwE

    $240

    All-Aluminum Design With 2 Rows of 1-inch Tubing
    Welded Seams Brazed Core Technology (No epoxy)
    Billet Fill Neck and Brass Petcock
    Rated Up To 650 Horsepower Cooling Capacity
    Standard Radiator Cap Included

    Sorry I was kind of late to chime in here.

    Bob
     
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  4. magic marouke

    magic marouke Well-Known Member

    So this one does have 1” tubing ? Don’t think it said on the duscription so this would fit mine to . Bob I just clicked on the link you posted in your thread . For some reason all the details show up on my phone but didn’t (or I couldn’t find them) in the work computer earlier . Looks like a good deal and I can get it from Jegs , thanks mate .
     
    Last edited: Apr 13, 2019
  5. Electra Bob

    Electra Bob Well-Known Member

    Tank was a drop in replacement for the stock tank on my 72 4 door HT so should work for you too.

    I swapped in a new fan clutch later but would be easier to do while you have the tank out and for the extra $35 or so worth doing.

    Cheers
    Bob
     
  6. magic marouke

    magic marouke Well-Known Member

    That’s good to know so I’ll definitely be going the same way . I’ve already put a new fan clutch in after the new water pump last year . The threads for the trans cooler all lined up and went right in yea ?
     
  7. Electra Bob

    Electra Bob Well-Known Member

    Everything is where it should be. I replaced the trans cooler lines with off the shelf braided steel lines because one of the originals was rusted at the wheel arch clip and split when I eased it out of the way. Unless you plan on replacing them make sure you remove the clips and flex them as little as possible.

    The expansion tank spigot was a shade oversize for the stock hose so I just replaced that with some other hose I had to hand.

    The tank does come with a knurled billet cap that fits over the base cap but mine was a loose fit so I just left it off.

    Good luck!
    Bob
    upload_2019-4-14_13-15-28.png
     
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  8. magic marouke

    magic marouke Well-Known Member

    Thanks mate . Ordered it today and even got the tax taken off . Will let y’all know how it goes
     
  9. magic marouke

    magic marouke Well-Known Member

    So new radiator came and installed. Really impressed with how good it replaced the original , didn’t have to mess with anything . Ran the car to get the air out with one of those non spill funnels someone here recommended. Must have had it running for over an hour to get rid of the bubbles . Drove it for a good 30 mins at about 55-60 also stopping . Temp stayed at about 190 mostly and then rising to about 205-210 . Dropped a little when I turned the heater off . Spiked to 240 for a few seconds then back again . Only did it once this time instead of four times in the same test drive before .
     
  10. Electra Bob

    Electra Bob Well-Known Member

    Hmmm - still sounds like it's running on the hot side unless your ambient temps are up in the triple digits already.

    Timing checked out?
    Is the expansion tank seeing big level changes when it gets hot and then cools?

    Put the front up on ramps and check levels. With the engine stopped and the radiator cap off give the upper hose some squeezes. That sucked a bunch of coolant when I did mine and showed a visible drop of level through the filler.

    Bob
     
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  11. Premier 350

    Premier 350 Chris (aka Webby)

    Could it be a gauge or wiring issue? The comment about 'spiked to 240" made me wonder.
     
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  12. magic marouke

    magic marouke Well-Known Member

    Bob , expansion tanks stays about the same and it was only in the 70's .

    Premier . that's what im thinking more now . it went crazy on the drive to work this morning . from 180 to 250 back and fourth in just a few seconds several times . I can check the wiring again I guess
     
  13. magic marouke

    magic marouke Well-Known Member

    Tried posting a video but won’t let me . It took 18 seconds to go from 180 to 240 and back again
     
  14. Schurkey

    Schurkey Silver Level contributor

    I'm starting to think there's a cylinder-pressure leak into the cooling system.
     
  15. bamboo72

    bamboo72 Well-Known Member

    Possible head gasket issue, sounds like same thing I dealt with. My engine is 70 with 90,000 miles.
     
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  16. Electra Bob

    Electra Bob Well-Known Member

    18 seconds from 180 to 240 and then back again to me sounds like either a malfunctioning gauge or a sticking thermostat.

    If the temperature shot up and stayed there then I'd be more convinced it was a head gasket issue.

    I'd start by checking the thermostat and for the $10 or so I'd go so far as to try a new one. And for around $20 you could pick up a cheap temperature gauge and temporarily fit it to that extra port on the radiator. That would give you a comparison of engine to radiator temp.

    Isn't this fun? :)

    Bob
     
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  17. bamboo72

    bamboo72 Well-Known Member

    Just passing on, exact same symptoms I had in mine, had replaced my radiator to aluminum and also found there was no thermostat in engine, installed temp gauge and saw the "floating" temp. New head gaskets on the engine, new 185 thermostat, stays at 185 all day long now. Good luck, I still run factory clutch fan with fan shroud on the 455.
     
  18. OZGS455

    OZGS455 Oh what a wonderful day!

    mine was cycling between 80C and 120C constantly...it was a sticky thermostat
    Good as gold now
     
  19. magic marouke

    magic marouke Well-Known Member

    Thanks for the reply’s guys . I can try another thermostat again . I did test the new one that it opened before I put it in and drilled a hole in it . Good idea about the port on the rad Bob and hooking a temp gauge to that . Does anyone recommend a thermostat brand ? I know you shouldn’t go cheap on these but I’m limited to car parts out here so can always get one online if someone has a preference . Trying to go the easier and cheaper route first obviously before I start tearing other stuff up .
    Again thanks for the help . I’m not as mechanicly smart as most of y’all so I appreciate everything.
    Simon
     

  20. Any update on that? My car has been presenting the same symptom as mentioned here.

    I took the engine out last year and when installed back, I put a quality mechanical temp gauge to have redundancy on panel indication (to the original electrical).

    Symptom: The are times in which the temperature is stable (180-200) regardless of the driving conditions and ambient temperature - which suggests there is not an issue with "system cooling capacity". However, sometimes - not always - during a change of operating conditions (from heavy drive to freeway and vice-versa, idle to mid-range, etc), the temperature jumps from 180~200 to 240-260 in a matter of 5-10 seconds. Engine is basically standard. Heater is removed and manifold plugged. New water pump was installed. The fan is a Derale 19in 6-blade rigid without clutch - basically, one cannot move more air than that. Changed radiator caps, both tested for pressure and both fine. The radiator was flushed and it is whistle clean and I am using a proper coolant mix (mostly water). I removed old thermostat and installed a new one after the issue was noted (both valves were externally tested for functionality and were fine) - and the symptom persists...

    Last week I put the car in a ramp and ran from cold to fully hot that another 10 min without radiator cap, let RPM to some 1500RPM and idle, ensured the level was always high with the use of a funnel - the whole lot... I went for a drive and, again, the "fast temperature raise" issue came back. I feel very confident the issue is air trapped - I cannot see another explanation of "temperature jumping from 180~200 to 240-260 in seconds" other than air in the system - which I am not being able to purge.

    Hypotheses at this stage:

    1) Looking in more detail, it appears that the thermostat housing outlet height AND new upper hose combination are sitting slightly higher than the return level of the radiator - rendering efforts to bleed air from the coolant system hard to say the least... I am going to buy another brand of upper hose and a replacement housing original to car from Rockauto to see if the situation improves, but I am not totally convinced this being the issue (as the temp gauge @ B4B is well below this level...).
    2) In an attempt to ensure the air was actually bleed out from the system, I drilled 1/8' @ 12 o-clock on older and new thermostat. I am starting to reflect this may not have been a good idea and will install an unmolested thermostat.

    I am running out of ideas now and any help someone could chime in would be appreciated!


    Cheers/Alex
     

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