1991 DeVille 4.9L water pump
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 29
HT4100 4.1, 4.5, 4.9 Discussion, 1991 DeVille 4.9L water pump in Cadillac Engine Technical Discussion; I been readin a lot about covers leaking and thermostat housings leaking, does this only include the northstar? I just ...
  1. #1
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    1991 DeVille 4.9L water pump

    I been readin a lot about covers leaking and thermostat housings leaking, does this only include the northstar? I just bought a 91 DeVille from my brother and he just put a new radiator in it but anitfreeze is still leakin out somewhere. I see some puddling up on the (what I presume to be) waterpump. did he buy a new radiator when it needs a waterpump?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,322

    Re: 1991 DeVille 4.9L water pump

    The '91 Deville does not have a Northstar. It has a 4.9 as the title says. The WP and radiator are pretty far apart so depemding on where you are seeing the drips, it should pretty easy to determine which is at fault.

  4. #3
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    Re: 1991 DeVille 4.9L water pump

    the water pump was put on 20K miles ago and the radiator about 150 miles ago but there is anitfreeze on both the ribs between the fittings on the radiator and if your standing by the r. fr. tire its puddling up next to the engine block on what i think is the water pump. I cant see where it's coming from and it wont do it idling in my driveway. I dried everything and went for a 5 mile ride and when I got back, so was the antifreeze in both places.

  5. #4
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,322

    Re: 1991 DeVille 4.9L water pump

    there is anitfreeze on both the ribs between the fittings on the radiator
    That sounds like the radiator side tank is leaking.
    if your standing by the r. fr. tire its puddling up next to the engine block on what i think is the water pump.
    That sounds like the pump or a hose perhaps. Hard to say without seeing it. A pump usually leaks through the shaft seal and then out the weep hole beneath the shaft.

  6. #5
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,022

    Re: 1991 DeVille 4.9L water pump

    Dry it real nice, idle it to operating temp, and then with the hood open and a flashlight in hand, run it to about 2000rpm and see what happens. You could also try some leak detecting dye and a UV light if you still cant find it.

  7. #6
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    Re: 1991 DeVille 4.9L water pump

    Cool, Thanks Sevillian I'll try that in the morning

  8. #7
    the recluse is offline Cadillac Owners Connoisseur
    Automobile(s): 2002 STS, 1991 Eldorado
    Join Date
    Feb 2009
    Location
    Jacksonville, FL
    Posts
    1,016

    Re: 1991 DeVille 4.9L water pump

    There is a by pass line just below the water pump from the block to the heater core; sometimes this rots and springs a leak at the bottom of the tube, so looking straight down on it you may not see it. It resides just behind the tire and suspension components, passenger side.

  9. #8
    Big Pip's Avatar
    Big Pip is offline Cadillac Owners Fanatic
    Automobile(s): '72 Coupe DeVille
    Join Date
    May 2008
    Location
    Central FL
    Posts
    104

    Re: 1991 DeVille 4.9L water pump

    I had a similar problem with a waterpump on my 4.5 ElDorado motor, not sure if it is the same on the 4.9 but...

    I had a plate behind my water pump which the gasket went bad on. The previous owner replaced the water pump and not the gasket behind this plate causing it to leak out and, well, adventually over heating. I know I had to take the whole front of the motor apart to get to it. I also replaced the timing chain also while I was there because when you remove this plate BAM- there is the chain.

    Good luck, I hate hunting for coolant leaks!

  10. #9
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    Re: 1991 DeVille 4.9L water pump

    I put her up on jackstands, high enough to roll my old ass under there, ran the car to normal operating temp., saw water/antifreeze dripping but couldn't see from where, so I climbed out from underneath, hit the throttle cam to raise the RPMs and sure enough, it squirted me right in the safety glasses. it's coming from that pan. whatever that pan is. looks like I have a job ahead of me. Timing chain ya say? May as well replace that too huh? Car has 137,000 miles on it. Seems the coolant on the radiator was a mist being thrown from the serpentine belt and coagulating/condensing on the radiator. Well, I'm glad it's just time and not money that I need a lot of for this fix. Time I have, money I don't!

  11. #10
    Big Pip's Avatar
    Big Pip is offline Cadillac Owners Fanatic
    Automobile(s): '72 Coupe DeVille
    Join Date
    May 2008
    Location
    Central FL
    Posts
    104

    Re: 1991 DeVille 4.9L water pump

    Glad to help! I did this in my driveway. It took me about 2 weeks to complete when I did this. Mostly due to NO motivation to do it. It isn't that horrible to change but be patient... I think I paid less than $20 for the chain.

    Good luck and enjoy your Caddy!

  12. #11
    behind-bars is offline Cadillac Owners Connoisseur
    Automobile(s): 93 Sedan Deville 4.9L
    Join Date
    Sep 2005
    Location
    Texas
    Posts
    1,005

    Re: 1991 DeVille 4.9L water pump

    FYI next time, or later this time, if you are trying to find a coolant leak get a pressure tester and pressurize the cooling system. It will get the same result as just letting the car idle, but with the engine off you can safely poke around.

  13. #12
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    Re: 1991 DeVille 4.9L water pump

    I found the leak. It's the water pump gasket. is this easy enough to do?, or do I have to remove all the components from the front of the engine first

  14. #13
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,022

    Re: 1991 DeVille 4.9L water pump

    You will need to remove the coolant overflow tank, battery, and serpentine belt. That's all I can think of at the moment. You might as well pick up a new pump while your at it. Those aluminum threads in the block will only take so many installations before they start to strip. I'd use alot of blue rtv and slightly under-torque them. I dont think there would be room to do a heli-coil in there.

  15. #14
    behind-bars is offline Cadillac Owners Connoisseur
    Automobile(s): 93 Sedan Deville 4.9L
    Join Date
    Sep 2005
    Location
    Texas
    Posts
    1,005

    Re: 1991 DeVille 4.9L water pump

    I think I replaced my pump without taking the overflow out, but it is easy to take out and clears some room; so might as well. Removing the battery is a must though. There is a pulley just above the pump that is easy to remove and allows a little more clearance for tools to get the back bolts on the pump. And please do not forget to put the pulley on the pump before you reinstall it. I kicked myself for not, Got the gasket installed and sprayed with the gasket adhesive, and was half way into bolting it back onto the engine when I realized I could not fit the pulley over the pump impeller because the frame was in the way. The pulley would not clear the frame when I took it out so I should have known. The 91 may have slightly different clearances then my 93 though so you may get lucky.

    If the pump is coming off anyway to replace the gasket I would replace the pump again to hopefully avoid repairs to that area in the near future.

  16. #15
    Starydr is offline Cadillac Owners Member
    Automobile(s): 1991 Cadillac DeVille, 73 Monte Carlo
    Join Date
    Sep 2007
    Posts
    11

    Re: 1991 DeVille 4.9L water pump

    I discovered that same problem with the water pump pulley. No clearance...all I needed was another 1/16th" but yeah, the frame is in the way. I was doing reading elsewhere in the forum and I read it was like a 5 or 6 hour job. I better get started early if I wanna drive this thing Monday. I DID try to put some stop leak in it to plug up the hole but to no avail. Shoulda known it wasn't gunna be as easy as pouring a bottle of something in the radiator. Thanks Guy's. I appreciate you.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting