Jeep details: 1995 Grand Cherokee Limited 5.2L with 178k miles and occasional blue puff of smoke when starting.

1. I have intermittent gurgling sound coming from the firewall area under accelerations from a stop. Heater core or air in cooling system?

2. Had to take the front bumper off due to lift kit and oversize tires. Curious how often someone has suffered a punctured radiator from not having some type of bumper to protect it. Really looking for a good reason I can give my wife so I can order a Hanson or Protofab bumper.

3. Has anyone had success with oil additives to quiet lifter tap like Liqi Moly or Rislone? I put 5w-30 synthentic in and now lifters are super noisy under acceleration when hot.

 

i had a gurgling/rushing noise from the same area when i filled the cooling system after my rebuild, mine went away after i was able to burp the system, so its probably air. turn the heat on full blast and if the air coming out doesnt get hot you probably have air trapped in there.

people get their radiators destroyed all the time without a bumper so it would be extremely prudent and financially responsible to put on an aftermarket bumper, winches also provide necessary protection as well.

and i add a ZDDP additive every oil change, not super familiar with the 5.2l but i know my 4.0 has flat tappet cams which need some kind of zinc substitute to stay lubricated and protected. diesel fuel may be an option too but id do some research just to be sure, our suburban had some lifter tick and we added diesel to the oil and it cured it.

 

Blue puff of smoke is most likely a bad plenum gasket which is very common on the 5.2

The gurgling sound is air trapped in the cooling system, you can try parking the jeep on an incline and while jeep is running remove the radiator cap and keep topping off the radiator until the thermostat opens, continue adding coolant until full, give the jeep a couple of revs while your at it to try and push any trapped air out.

 

Say what? Never heard of adding diesel to the oil before.

 

Please! My GRANDFATHER used to use kerosene to clean out his model T engine just before an oil change! Kerosene (or diesel) shouldn't be used for long because it's a good detergent but lacking in lubricity. Don't use more than 10% and revs less than 1500.

You can prevent air blockage in the heater core by installing the hose from the thermostat to the lower pipe on the heater core. Air bleeds out naturally that way.