1993 Chevy Astro REPLACED PISTONS & RINGS NOW ENGINE DR

POET042005

MECHANIC
1993 CHEVROLET ASTRO
6 CYL
2WD
AUTOMATIC
130,000 MILES

I RECENTLY REPLACED my piston rings and two of the of the pistons while keeping the other 4 original piston. I also replaced the crankshanft, caps and main bearings. I got the van running. It runs great at idle but I noticed the motor's temperture seems to get lightly higher then what it should be without over heating. The crank can be moved by hand but it is slightly harder to move then normal.

My problem is that when I took the van for a test drive it accelerated with excessive engine Drag and I can hear the pressure at top dead center from one or more of the pistons a I increae acceleration. But as I aid it idles fine when sitting and there is no knocking at all.

One other thing I no the timing is not set 100% to spec although I did get it set as close as I could get it. Is it possible that the timing could be causing the drag. I need help I have tore the motor apart twicw already and can't seem to get it right.

6 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

If the timing is out, it will have an affect on performance. Is there a reason why you can't get it where it needs to be?

Also, what temp is the engine ruinning at. It should be around 200 degrees.

Joe

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Monday, June 1st, 2009 AT 9:10 AM

POET042005

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Well as far as the answer to your first question I currently do not own a timing light and am trying to set the timing by ear. As for the second question I'm not quite sure what the engine temp is reaching I actually never new how to determine how you would go about measuring the engine temp. Could you explain how that's done, would love to know.

I want to add two other things first I checked for codes and found that a few different sensors are reading error.

Map sensor

Knock sensor

Ignition bypass error

Coolant temp sensor.

Second when setting the distributor where the #1 prong is lined up with the rotor should the #1 prong be pointing towards the air cleaners as if in the 12 o'clock position?

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Monday, June 1st, 2009 AT 10:52 AM

JACOBANDNICKOLAS

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They actually make a thermometer that is placed in the top of the radiator. (NEVER OPEN WHEN HOT). As far as the codes, three of them can cause the engine to run poorly. The, a knock sensor will play with the timing, map sensor will play with fuel mixture, and the coolant sensor can do the same. If the car continues running and not dieing on you, chances are the map sensor isn't the problem but rather the coolant or knock sensor especially if it seems to be running too rich. Regardless, you need to get it in time. See if the local parts store will rent a timing light to you. That may be half the problem.

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Monday, June 1st, 2009 AT 8:10 PM

POET042005

MECHANIC
134 POSTS

Ok I bought a timing light set timing to spec, replaced water pump and intake gaskets, motor runs great starts right up and cooling sytem is now working correctly, yet I still have the problem with the slight drag on acceleration as if the trans is reving up before it goes into gear yet all gears are working I was thinking to just swap the trans but I was wondering if you may have any other ideas as you have been very helpful in this.

One other problem even though I no the cooling system is functioning well do to the heavy heat im getting and fluid circulating through the sytem, my tempreture hand is not reading it just sits at C, I took a multimeter and checked the harnes to the cooling sensor and it read between 4.6V and 6V now im assuming it read that low because of the fuse it runs to or theres high resistance keeping the sensor from 12 volts.

Let me know what you think about these two new problems.

Richard

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Wednesday, June 3rd, 2009 AT 11:22 PM

JACOBANDNICKOLAS

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109,885 POSTS

IS the trans slipping? Make sure the fluid is full and clean. As far as the sensor, it should receive 12 volts, so chances are there is a damaged wire or bad connection.