Coolant in oil after rebuild of 455

Discussion in 'Race 400/430/455' started by Danny Martin, Feb 25, 2019.

  1. Danny Martin

    Danny Martin Member

    I just had a 455 rebuilt and I have a large amount of water getting into the oil. It only ran for 2 minutes and the oil looks like milk. I upgraded the stock heads to the Edelbrock heads and Edelbrock intake. I did buy a new timing chain cover, but it visually looked the same. What did I miss? I pressure tested the cooling system at 15 pounds and lost 5 pounds pressure in 5 minutes.

    Has this happened to anyone before? Where should I check first? Is there a gasket in wrong?

    I have a bore scope I can use.

    Also, once I fix this, what's a good way to clean the engine now that it has water and oil throughout? Is just a few quick oil changes enough?
     

    Attached Files:

  2. greatscat

    greatscat Well-Known Member

    What head gasket did you use, also its possible its installed backwards.
     
  3. johnriv67

    johnriv67 Well-Known Member

    If you see water pooling up underneath the intake on the valley pan, it’s quite likely to be a head to intake water port that isn’t sealed
     
  4. Danny Martin

    Danny Martin Member

    Is there a water port that I should have sealed before putting the head on?
     
  5. Danny Martin

    Danny Martin Member

    I used the one that was sold with the Edelbrock heads.
     
  6. johnriv67

    johnriv67 Well-Known Member

    Here, I think we need to know more about your build. If you wouldn’t mind, go down in a list like this:

    Block year
    Head gasket part number
    Stock oiling system?
    Stock pistons?
    Cam?
    Stock Timing cover?
    Did you use RTV in the right places?

    This will help us get a much better idea, especially because the later cylinder heads used a different pattern of head gasket to seal everything up
     
    Last edited: Feb 25, 2019
    Kingfish likes this.
  7. Danny Martin

    Danny Martin Member

    Will the attached photo help?
     

    Attached Files:

  8. greatscat

    greatscat Well-Known Member

    I'm not sure what gasket was supplied. Could be in conflict with the year block. Later 71-76 blocks had oval water jackets, a gasket for round jackets will leak.Also its possible to install the head gaskets wrong. What intake gasket was used, steel bathtub type?Double check front cover, make sure the bolts are all tight.
     
  9. johnriv67

    johnriv67 Well-Known Member

    AHHH NOOO, he has the dreaded 218/218 Comp cam. I knew I recognized that part number....

    Dang, I wish we were able to guide you earlier through this. This cam has a terrible reputation and quits making power by roughly 4800 rpm. Well, if you end up having to pull things apart to get to the source of this oil/watering issue, listen to many smart guys here on the board about different part choice, because that cam will not get you where you would otherwise be with even a stock Stage 1 grind from 1970.

    I also notice you have ARP hardware throughout the engine, which will likely allow it to spin a little over 6 grand. You have about 1200 more rpm to work with if you pick a different cam, in time
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Who actually assembled the engine? If it was a machine shop, I'd be talking to them immediately. Anti freeze will damage bearings fairly quickly.
     
  11. Danny Martin

    Danny Martin Member

    I did call the machine shop and the first thing they told me was to hurry up and get the coolant away from the bearings. I'll get that done tonight. Then I'll start scoping inside the timing chain cover and through the PCV port in the back to try and locate the leak.
     
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I'd pull the engine and back to the machine shop it would go. Not your job to figure out where the leak is. It's their responsibility plain and simple.
     
  13. 67nitrouspig

    67nitrouspig Well-Known Member

    Just out of curiosity, did you have the shop do the oiling mods to the block for you? I know when I was reading through Jim's sticky showing how to do it one of the sections he said you could drill through into the water jacket when enlarging the hole, albeit he was talking about the 400s and 430s, but if the shop doesn't do Buicks often maybe that would be something good to have them check or if you are tearing it down before taking it back checking to see if maybe that is what happened.
     
    johnriv67 likes this.
  14. greatscat

    greatscat Well-Known Member

    Also 70 455's and real early 71's needed the oiling mods too.
     
  15. 67nitrouspig

    67nitrouspig Well-Known Member

    Yes, sorry my wording was bad there I wasn't trying to say the 455s didn't need the oiling mods, I was trying to say it seemed like Jim was saying it was easier to drill into the water jacket with the 400 and 430s since he specifically mentioned those two engines when talking about the potential to drill through into the water jacket. I think it could happen with the 455s as well I just noticed he pointed those two out specifically in that portion of the thread.
     
  16. greatscat

    greatscat Well-Known Member

    Yep, the later 71's and 72 on had the main feed already opened up to 5/8"
     
  17. Danny Martin

    Danny Martin Member

    First; thanks for everyone's help.

    Well, here's an update. Pulled the PCV valve. With the cooling system under pressure, you could hear the water spraying at the back of the engine. Put a camera in the PCV valve opening and it appears to be coming from the passenger side. I'll pull the intake tonight, but here's what it appears to be. I added a temperature gauge and sensor to the car. It "appears" that the water is spraying from the underside of the intake where I (I mean my son!) screwed in the temperature sensor to the rear of the intake near the PCV valve. Could the sensor been too long and cracked the bottom of my intake?? If so, that's a new one for me! I'll pull the intake tonight and let you know. Uggggg!!
     
  18. dan zepnick

    dan zepnick Well-Known Member

    Wow,that would be a new one! I'd install the temp sender up I front by the thermostat housing.
     
  19. Danny Martin

    Danny Martin Member

    I kept the idiot light sensor installed in the port near the thermostat housing. I wasn't sure if I could use the gauge sensor for the idiot light and the gauge, so installed both. The only other port that size was in the rear of the manifold near the PCV valve.
     
  20. Quick Buick

    Quick Buick Arlington Wa

    Actually That is a idlebroke pis poor part. Idlebroke has absolutely no quality control..

    Ive received intakes that teeter tooter while laying on the block and heads. Their solution thick gaskets.

    There pipe threads some fittings go in 2 rotations others bottom out.

    Boils down to it Idlebroke makes Cut Rate Auto Parts CRAP.
     

Share This Page