I have a 89 ford with 4.9L. Reinstalled a rebuilt motor, put in a gallon of gas to mix with 2 year old gas in tank (tank had about a gallon of gas in it). Now i have bent push rods. Shop wants 500.00 to prove it was the old gas that cause the bent pushrods. Machinist will rebuilt heads for 150.00. It is easier to come up with 200.00 than 500.00. I had parked this truck because it started knocking shortly after putting new timing gears. I may have bent something when the gears went out, since it happened while i was driving. When i get the heads back from machinist are there any adjustments i need to do on the valves? I think these are hydraulic lifters. Not a professional but i ususally do my own repairs.

 

Bad gas is in no way going to cause bent pushrods. Unless the engine absolutely did not start, flooded the cylinder and hyrdo locked it, no way. Even in that case you're looking at bent connecting rods, not pushrods. Have to call BS on that one.

 

When I rebuilt my 94 5.8 with hyd rollers I discussed this with the builder and they do need to be set right and shimed up if compressd to much. my choice was to let him do it since its a daily driver and am glad I did. All is well now and I love the way it runs. But you can do it yourself.

 

I 2nd the bs call

 

This was my first thought, then i started reading some of the threads in the engine forum, and i saw where someone was having problems with bent rods. In one of the replies they answered it was a possibility. I don't have 500 to bet that bad gas was the problem. I guess if the valves gummed up and got stuck a bent pushrod is a possibility. I'm having the truck towed back and i'll pull the heads and have it cleaned up. Is there a special procedure for purging the fuel lines. I thought i could open up fuel line somewhere near the end and let the fuel pump do the purging for me. Will this procedure work for getting old fuel out? I was told i might need to replace the injectors also., I not sure what to believe.

 

Well my theory is this. If your gas was thick enough to gum up your valves that quickly, it never would have made it through the fuel lines & injectors. I just can't buy that story, and certainly not for $500. Best thing you can do is stay far far away from that shop.

Now improperly adjusted valves, sure, that's an easy way to bend pushrods, I've done it.

 

I agree. Just say no to that shop. Valves should only compress the hydraulic about 30 thousands if memory serves me and sometime it dont so consult with a reputable engine builder.

 

My thinking also, towed the truck home and have proceeded to tear out the head. If the pushrod got bent should i replace all pushrod and lifters? I'm going to check the timing marks on gears, anything else a I might look at?
I bought the motor from the same people who wanted to tear down the engine. they said if it was their fault they would do the work for free, but if i installed wrong i would have to pay for the work. I would say that their opinion would be a little bias. Not taking the chance.

 

Push rods yes lifters no. Hyd rollers can go 300 k with no problem. But the culprit that caused all this has to be found to rule out lifters.

 

The machine shop says gummed up valves. I think i saved myself some money. Now i need to purge gas line. I took the tank off and dumped out the old fuel. I'll get some type of additive on the way home to put in tank. I still have the old injectors. I can replace o-rings and reinstall the old ones for now. Got a new fuel filter. I would say that is good. What does a garage do when they purge gas lines?

 

Just disconnect the fuel line up at the motor and run the pump to flush a couple gallons of gas through. That is all i do when our not so smart customers fill there Corollas up with diesel fuel.

-Jon

 

Gotta do that when people mix up the oil injection tank and the fuel tank on 2 stroke motors. Then they're surprised and say "i thought it was a little odd it only held 1 gallon of gas" That's the #1 n00b mistake, close behind is just not adding oil at all and wondering why a mile out on the water the motor seizes even before the temp alarm goes off.

 

I put old gas in my 1993 f-150 6 months apart and had the pushrods bend on the number 3 and 6 cylinder. It is the old gas that causes the problem. I replaced the rods and everything was ok. I will never use old gas again in a car engine.