Anti-freeze in oil

My son bought a 1988 toy truck with anti-freeze in the oil. The head gasket is a given. I have been told that the head bolt require a special silicone to seal them, and if they do not have it they will let the water into the oil. The engine has a fresh re-build and the spark plugs show no signs of water. Any help would be appreciated, this is my "first time" with a toyota.

Reply to
ApacheDriver
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There are good instructions to be found on the web for head removal replacement. I haven't heard of a special silicone but that doesn't mean it doesn't exist. I'd make sure the head and block are flat. The timing cover can also be the problem. The truck I have had the timing cover damaged early in life ... the dealer replaced the head gasket, then went back and did the cover which was the problem.

Reply to
JeB

It sounds like the timing chain may have worn a groove in the timing cover. The chain can stretch with use and age where the oil pressure operated tensioner can't take up enough slack which will break the drivers side plastic chain guide. All this ends up letting the timing chain rub on the timing cover until it cuts a groove around 3/16"-1/4" deep hitting a coolant passage. It makes a big mess, pull the head, timing cover and have a look. clean the resulting sludge from everything possible (radiator, engine block, head, oil pan, etc). Hopefully it wasn't driven too many miles with the compromised oil wearing on the motor. This does happen as I am currently repairing a 1990 toyota pickup,

22re with the above problem (clean spark plugs, good compression, mixed coolant and oil). There is a fix (which I am doing) for the problem, a few companies offer metal timing chain guide(s) with hard rubber bonded for a whole lot more durability. (check: engnbldr.com) As far as the silicone question, never heard of it nor used anything on head bolts or head gasket.
Reply to
firepumper1

It sounds like the timing chain may have worn a groove in the timing cover. The chain can stretch with use and age where the oil pressure operated tensioner can't take up enough slack which will break the drivers side plastic chain guide. All this ends up letting the timing chain rub on the timing cover until it cuts a groove around 3/16"-1/4" deep hitting a coolant passage. It makes a big mess, pull the head, timing cover and have a look. clean the resulting sludge from everything possible (radiator, engine block, head, oil pan, etc). Hopefully it wasn't driven too many miles with the compromised oil wearing on the motor. This does happen as I am currently repairing a 1990 toyota pickup,

22re with the above problem (clean spark plugs, good compression, mixed coolant and oil). There is a fix (which I am doing) for the problem, a few companies offer metal timing chain guide(s) with hard rubber bonded for a whole lot more durability. (check: engnbldr.com) As far as the silicone question, never heard of it nor used anything on head bolts or head gasket.
Reply to
firepumper1

It sounds like the timing chain may have worn a groove in the timing cover. The chain can stretch with use and age where the oil pressure operated tensioner can't take up enough slack which will break the drivers side plastic chain guide. All this ends up letting the timing chain rub on the timing cover until it cuts a groove around 3/16"-1/4" deep hitting a coolant passage. It makes a big mess, pull the head, timing cover and have a look. clean the resulting sludge from everything possible (radiator, engine block, head, oil pan, etc). Hopefully it wasn't driven too many miles with the compromised oil wearing on the motor. This does happen as I am currently repairing a 1990 toyota pickup,

22re with the above problem (clean spark plugs, good compression, mixed coolant and oil). There is a fix (which I am doing) for the problem, a few companies offer metal timing chain guide(s) with hard rubber bonded for a whole lot more durability. (check: engnbldr.com) As far as the silicone question, never heard of it nor used anything on head bolts or head gasket.
Reply to
firepumper1

Thanks for the info. The engine compression test showed 120, 130, 95, and

110 and all held the pressure. The pressure test on the cooling system did not fare as well. I can hear air escaping from the front of the head behind the timing chain. Hopefully that indicates a bad gasket. Any help out there?
Reply to
ApacheDriver

A good rule of thumb for compression testing is all cylinders need to be within 10% of each othe. With your 120 as the median (132 high/108 low) that 95 psi seems out of line, 110 psi borderline.

Reply to
firepumper1

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