lilred626

No Compression At All

9 posts in this topic

I am picking up a 1995 Mazda 626 LX with what I can only assume is a horribly blown head gasket. I did get a chance to pull the valve cover, and the cams are moving, timing belt looks pretty good, and feels plenty tight. There is really no compression at all. It just sounds like a starter whirring away with a light huff out the intake every now and then. The oil is VERY low with some tell tale milk shake on the end of it. Coolant looks fine. I do not need this car and just going to work on it as a project/toy since I can get it for nothing and the rest of the car is in pretty good shape.

I have worked a few cars with blown head gaskets, but never one that left all the cylinders dead like this. Normally at least a few have compression. Is this common on this engine? I guess I might be hunting a new engine in the end, but oh well....

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Sounds like perhaps the valve timing is way off. You said the belt looked good...did someone recently try to replace or repair it? Zero compression is hard to believe, even with a blown head gasket...you should still get some low readings.

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Nobody has had the timing belt off of it in the last few years. I have done the minor upkeep on it, things such as spark plugs, wires, battery, acc belts, brakes. The car belonged to a friend of ours . But no timing belt. The belt on it is a gates and did not look bad, I.E. Teeth not rounded, belt still tight. I did not ensure that the marks line up though as it was just me on the side of the street. I did not do a proper compression test, so there might be a little, but not enough to even make the starter sound different. It sounds like a bad starter not engaging the flywheel when cranking, but the engine is turning. I guess when I get it, I will first verify timing is on, then do a real compression/leak down test and go from there.

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a wile back when i got my 94,compression read 10/5/5/2-all from bad water pump leading to badly blown head gasket and badly warped head and valves.i replaced the motor because i was afraid the rings were set/bad from it getting that hot.it cranked a lot like you descrebed.i hope yours isn't that bad.

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a wile back when i got my 94,compression read 10/5/5/2-all from bad water pump leading to badly blown head gasket and badly warped head and valves.i replaced the motor because i was afraid the rings were set/bad from it getting that hot.it cranked a lot like you descrebed.i hope yours isn't that bad.

Yeah me too, because all im gonna do is head gasket and resurface the head along with timing kit/water pump kit. Hoping that gets it running. According to owner, it didnt get hot first, but I doubt she ever looked at the temp gauge.

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Just as a follow-up. I got the car home and the timing is WAY off. The exhaust cam is right on at TDC, but the intake cam is about 130 degrees out. The oil hasnt been changed in a long time.... That would explain the low oil. I will throw a timing set/water pump at it first and then see what I get. Fun stuff.

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Another follow up.. IT LIVES!!! I got some time to mess with it today, I pulled the Timing belt off and under the cover had oil all over it. This got me curious, so with further inspection I found that the oil filter was about to come off!! The entire backside of the engine was soaked in oil. Dont know how I missed that on my first look see... I can only assume that the oil made its way into the Tbelt area just enough to cause it to slip the intake cam .Engine was 3 quarts low..... That cant be good for anything. I de-greased the thing, put the belt back on in time. The tensioner and water pump looked really good once I got the oil off. The engine fired right up and sounds happy. Now that I know what im doing, I will run this setup for a while and see. I will order a timing set and have on hand for when this one slips again. I love not worrying about valves whacking pistons :-)

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thats fantastic news,im glad you got you car back.;)

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