Edmunds Answers

Voted Best Answer

  • avatar 0patience 03/27/11 3:03 pm PST

    "any leaking of antifreez at the intake manifold would show up either as in the oil or external dripping which was not present"
    Not necessarily. I've seen many of these engines leak on the intake and there really wasn't any external signs on the engine.
    On one engine, the leak was out the back side of the intake and down the engine where the starter is. It was so slight, that it never hit the ground.
    The only way it would show up was to do a coolant pressure test on it.

Answers

  • 0patience 03/27/11 1:53 am PST

    The only way to check heads for cracks is to magnuflux them or there is a chemical dye that you can use to detect cracks.

    But the 3.1 is notorious for leaking coolant out the intake gasket.
    Did you do a combustion leak test BEFORE you pulled the heads?
    Use the Answer this Question button to reply.

  • bobwmontana 03/27/11 9:32 am PST

    thank you for replying. the only pre-teardown combustion check i did was to apply 100 psi. to each cylinder ( valves slackened ) and
    watched for a pressure rise in the blocked off cooling system, without results.normally i would have warmed the engine and applied air pressure to the cyls.and watched for boubling at the filler neck.any leaking of antifreez at the intake manifold would show up either as in the oil or external dripping which was not present.i can't be sure the previous boubling at the filler neck wasn't from my not bleeding the cooling system each time i topped off the low coolant..i have only owned the car 2 months. the gaskets had to have been changed quite some miles ago ( guaging on the grime build up on them ) also the eng preforms remarcably well as it uses no oil and gets 30+ mpg and no blow by in the crankcase past the rings...thanks again...bobwmontana@yahoo.com/406 266 3226

  • laltazan 03/27/11 10:46 am PST

    The manifolds on this engine sometimes leak into the intake ports. When this happens there may be no external leak, no oil in the coolant or coolant in the oil, they can be tricky. Here's an article on the topic


    Good Luck

  • 0patience 03/27/11 3:03 pm PST

    "any leaking of antifreez at the intake manifold would show up either as in the oil or external dripping which was not present"
    Not necessarily. I've seen many of these engines leak on the intake and there really wasn't any external signs on the engine.
    On one engine, the leak was out the back side of the intake and down the engine where the starter is. It was so slight, that it never hit the ground.
    The only way it would show up was to do a coolant pressure test on it.

  • Stever@Edmunds 03/27/11 4:57 pm PST

    You can reply in this thread by clicking the Answer this Question button and that will help keep all the information in one spot. Thanks!

ADVERTISEMENT

Top Buick Century Experts View More

Rank Leader Points
1. MrShift@Edmunds 275
2. karjunkie 135
3. zaken1 100
4. 0patience 80
5. Stever@Edmunds 55
6. docj 45
7. lokki 45
ADVERTISEMENT