95 RRC loosing coolant in expansion tank

[silvermax]

So Ive been noticing I'm losing coolant in the expansion tank . No overheating and power seems fine, no smoke or smell and no drips in driveway and no coolant in oil.

I did replace the radiator about 2k miles ago and "think" I burped properly. Also did a test and didn't refill to see if it has a sweet spot, put almost 1000 mile on and seems expansion tank is almost empty again.

Is this common or a bigger prob, what tests can I do to eliminate risks?

Thanks

 

[robisonservice]

There are two possibilities for coolant use. The coolant is leaking out of the engine, in which case you should be able to see it, especially with a cold engine pressure test. That is most likely. Remember that many leaks don't drip as they just blow away in the wind but you can still see the traces underneath. The second possibility is that the motor is consuming the coolant through small cracks in the block or via head gasket leakage .

 

[silvermax]

Great advise John, thanks! I have really only read on pressure tests when warm, is there a different procedure or as easy as doing the test when cold???

Ill get the kit and have a go...and cross my fingers its not a head gasket.

 

[silvermax]

Just a follow up. So my heater wasn't working when all this was going on, so fixed heater K127 relay, and started her up without cap and as it heated up she burped, swirled and gurgled and lost most coolant in OF Tank. Drove her and filled up again and capped as I squeezed the top hose, and after 150mi all so far is well! When I changed the radiator I didn't take into account the heater need to fill and burping is essential.

So far so good and if Anything changes I'll take Robinsons advise and hope for the best!

 

[silvermax]

Spoke to soon, now it's going through coolant quickly and noticed faint white smoke on startup. So here's the dilemma, these symptoms point to HG but also have a ticking only when it's warm and not all the time, usually only after a long drive...could be slipped liner?

I'm pretty handy and have restored a D90 and a few old bronco's, but was lucky to mostly have strong engines. Should I attempt the HG myself or buy a used 4.2 and try to drop it in, is either of these to difficult for a weekend warrior or do I bite the wallet and pony up at the shop?

 

[57loboy]

Get the manual if you don't already have one, buy good parts - like new heads bolts, and have the pride of knowing you did it yourself. Ticking could be lifter. Good time to check/replace them when you've already got the top of the engine off.

 

[discostew]

Ticking could be the steel insert in the rocker , the insert that the pushrod rests in . With the rocker shaft off the truck try to turn the inserts in the rocker arms with a pocket screwdriver in the oil hole . If the insert turns then its loose and probably ticking. If your loosing a lot of coolant it could be the front cover pissing into the oil pan . What's the oil look like ?