comanchejoe Posted December 10, 2009 Share Posted December 10, 2009 Alright so I got ahold of a 92 comanche today for 300 bucks with a salvage title... but it is probably the cleanest one I have personally seen. I do have some questions about some engine noise though... here is the run down. The previous owner overheated it and the head ticks pretty good... What I am not sure of is if this is caused by the overheating or not... It does not smoke at all, the oil has no apparent water in it and it is not milky, and it runs very strong.... With all of this being said I am ruling out that the headgasket seems to be fine as well as having no head warp... I am imaging it has a bad lifter or more than one bad lifter... but would overheating cause this? He said he started noticing the ticking after the overheting incident... this makes me think that it is more than just the lifters... I plan on doing a full tune up, replacing the o2 sensor, crank sensor, etc.... Any other thoughts on what this is? I will say that it does not go away when it get warm and sometimes it is louder than other times.... :help: Link to comment Share on other sites More sharing options...
Oizarod115 Posted December 10, 2009 Share Posted December 10, 2009 it really depends on HOW loud it is... they generally all make alot of noise... some did it from brand new, some developed it over time, and some never do it. also be sure you've got plenty of oil pressure cause this can be associated with it often. Link to comment Share on other sites More sharing options...
Pete M Posted December 10, 2009 Share Posted December 10, 2009 what's your build date? :brows: (sticker on the drivers door) Link to comment Share on other sites More sharing options...
jeepcoma Posted December 10, 2009 Share Posted December 10, 2009 FWIW my '91 HO runs great, exactly as you described, and has the same noisy lifter problem. Once it's warmed up, and I mean really warmed up enough to get the oil pressure down around 20-30 psi at idle, the ticking seems to go away. You could try some miracle additive like marvel mystery oil, or a cleaner like seafoam, and see if it goes away or lessens. One other common issues is a cracked exhaust manifold, which will tend to be louder at first startup when cold and lessen as the manifold warms up (how much it quiets depends on the size of the crack). If the overheating really caused some serious damage you'd be burning coolant, so if you're not loosing any it's probably nothing serious (it easily could have been ticking before the overheating incident and the guy just never paid attention to it until after when he was listening for problems); take a long wooden rod or dowel and stick one end against the engine and another against your ear to probe around the engine to determine where the noise is coming from and you can probably narrow it down to one cylinder or lifter which you can then inspect. A compression test never hurt either if overheating damage is suspected. Link to comment Share on other sites More sharing options...
Eagle Posted December 10, 2009 Share Posted December 10, 2009 It may not be the lifters. The 4.0L is not an overhead cam engine. The lifters push on the pushrods, which in turn actuate the rocker arms, which are what actually push on the valves. Over time, all those parts may get a bit worn. If it's just a light ticking, it's probably normal and doesn't mean anything if the engine runs strong. Try removing the oil fill cap from the valve cover and see if the noise is louder. If so, it could be the pivots that the rocker arms rotate on. Another possibility is that the exhaust manifold may have loosened up, especially if it overheated, and the tick is actually a small exhaust leak. If that's the case, simply tightening the manifold bolts may cure it. Link to comment Share on other sites More sharing options...
comanchejoe Posted December 10, 2009 Author Share Posted December 10, 2009 what's your build date? :brows: (sticker on the drivers door) I will check on it... would be interesting to know :hmm: My oil pressure seems to stay right around 40 at all times... I looked in the radiator and there is no coolant left it seems... or at least not alot... I may try filling it and see if I have any smoking issues... I went and started it up this afternoon and the noise seemed to get louder as the tempurature began to rise... I won't be able to really look at it until tomorrow afternoon... hopefully I can find something. Link to comment Share on other sites More sharing options...
Eagle Posted December 11, 2009 Share Posted December 11, 2009 I went and started it up this afternoon and the noise seemed to get louder as the tempurature began to rise... That's because the oil gets thinner when it's hot. But don't run it if you don't have coolant in it. Link to comment Share on other sites More sharing options...
comanchejoe Posted December 11, 2009 Author Share Posted December 11, 2009 Wait, why can't I run it without coolant? :dunno: j/k :yes: Ihave only been running it up to 190 and turning it off just to try and locate the noise... I will give you guys an update tomorrow when I have time to actually look at it... thanks for the help! Link to comment Share on other sites More sharing options...
Eagle Posted December 11, 2009 Share Posted December 11, 2009 Wait, why can't I run it without coolant? :dunno: j/k :yes: Ihave only been running it up to 190 and turning it off just to try and locate the noise... I will give you guys an update tomorrow when I have time to actually look at it... thanks for the help! Two points: First, the scale on the temp gauge is not linear. There is no marking for 190, so you have no way of knowing where 190 is on the scale. More importantly, the temp sensor for the gauge is at the top back corner of the head. If you are low on coolant, that's where there will be an air pocket. The sensor will not be in flowing coolant, so it won't react quickly to the engine heating up. By the time it thinks it sees 190, the actual temperature will be significantly higher. Link to comment Share on other sites More sharing options...
Pete M Posted December 11, 2009 Share Posted December 11, 2009 pulling that sensor is the way to bleed out the last bits of air. try to get the rear of the truck higher than the front, then slowly unscrew the sensor and start up the truck. You don't have to completely remove it, just unscrew enough for the air to bleed out. Be sure to wear good eye protection, have a rag over the sensor in case to pops free, and have someone else start the truck so that they can kill it if anything goes wrong. :thumbsup: Link to comment Share on other sites More sharing options...
comanchejoe Posted December 11, 2009 Author Share Posted December 11, 2009 Good tips guys! thanks! Checked it all out today... Noise is definately coming from the head on the left side. Did the screwdriver to on the valve cover trick and listened through the screw driver... Noise seems to be almost dead center of the head on the left hand side... I will take the valve cover off tomorrow and see if any of the push rods seem spongy... Went to autozone today... got new thermostat, water pump, serp belt, plug, wires, 02 sensor, crank sensor, temp sensor.... Link to comment Share on other sites More sharing options...
freakjeep93 Posted December 12, 2009 Share Posted December 12, 2009 [quote name="comanchejoe" Went to autozone today... got new thermostat' date=' water pump, serp belt, plug, wires, 02 sensor, crank sensor, temp sensor....[/quote] congradulations you have now entered the world of jeeps this will be oftern . just remember Just Empty Every Pocket Link to comment Share on other sites More sharing options...
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