Timing belt tension for a 1989 Pontiac Lemans 1.6L

[Jerry Farmer]

Hi there. I have a 1989 Pontiac Lemans 1.6L vlaue leader. I am doing a head gasket and timing belt since this little engine runs great and has 198K miles on it and has never been touched. I bought the car back in Jan. of ’07. Ok the factory service manual simply says “set to specs” regarding the timing belt tension but does not have the specs anywhere in the book.
This engine does not have an idler pulley for tension. It is adjusted via turning the water pump. Does anyone have an idea of what the tension should be? Also another question.
Every since I have owned the car there has a been a little issue of the famous “chocolate shake” syndrome at the oil filler cap. There is a hose that goes to a fitting at the top of the cam carrier that goes over to the bottom of the air cleaner which port is between air filter element inside and between the throttle body. There is nothing in the cam area, in the oil or the antifreeze. It is like condensation or something causing it.
Yes I was able to obtain new head bolts also, not an easy task at all.
Something else also. At the front side bottom of block along the oil pan mating surface at the rear corner by the bell housing. There is a little plug I can pull out with no resistance at all. It has a black cap and like a vinyl or something tube that goes right into an insert in the rear of the block. In the FSM for the 1.6 is has the technical drawing and it is there but says nothing about what it is.
Any help would be greatly appreciated.
I did upload a short video of this thing on you tube. If you search You tube for a 1989 Pontiac Lemans it will come up with a result showing the bottom of the head.
Again thank you.

Topic

[Richard Kirshy]

Did some looking.. not a lot of information available.
As to timing belt tension …
Generally( but not always ) is to have between 1/4 to 1/2 inch deflection depending on the distance at the mid point of the longest distance between pulleys.
7 to 10 inch span between pulleys ~ 1/4 inch deflection.
13 to 16 inch span between pulleys ~ 1/2 inch deflection.
when pressing down with ~3 lbs of force.
Can’t say what this black cap is, could be some type of breather.
Back then car companies were doing various things to engines to try to meet emissions.

Concerning your “chocolate shake” syndrome …
Do you notice this mostly in cold weather and/or using the car on a lot of short (around town trips)
If so, your dealing with condensation.
Your not driving long enough to allow the oil to ” dry out ”

[Jerry Farmer]

Thanks for responding. When I pulled the belt it had about 1/4″ deflection. The belt for all honesty shows no signs of wear. You can still indent with your finger nail, no gloss and cracks are not there. As to the chocolate shake. Anytime of year, after long road trips or what ever. The little plug is baffling. It has no holes in it and I can stick a piece of wire into the crank case.

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