Dead end Joe 1 Posted July 31, 2011 Does your XJ have a belt driven fan or is it all electric? If you put a 3 core radiator in and moved the shroud back on the fan then the fan is not sticking out of the shroud far enough and causes turbulence. One half of the blade needs to be sticking out of the shroud. I did the same thing to my TJ and it ran hotter with the bigger radiator until I trimmed the shroud. Share this post Link to post Share on other sites
Number7 89 Posted July 31, 2011 Does your XJ have a belt driven fan or is it all electric? If you put a 3 core radiator in and moved the shroud back on the fan then the fan is not sticking out of the shroud far enough and causes turbulence. One half of the blade needs to be sticking out of the shroud. I did the same thing to my TJ and it ran hotter with the bigger radiator until I trimmed the shroud. It has duel electric fans that have built in shrouds. I can feel air being sucked in when placing my hand in front of the grill. George:cool: Share this post Link to post Share on other sites
dzJeepChic 2,897 Posted July 31, 2011 So I talked to my friend Tuffnuttz on NAXJA who is a mechanic and one of the things he mentioned was doing the compression test dry and wet to see if theres a difference. George had already tried doing that, but he did it again today. I found this ariticle which explains the theory: If compression is low in one or more cylinders, you can isolate the problem to the valves or rings by squirting a little 30 weight motor oil into the cylinder through the spark plug hole and repeating the compression test. The oil temporarily seals the rings. If the readings are higher the second time around, it means the rings and/or cylinder is worn. No change in the compression readings tells you the cylinder has a bad valve. Here's Compresion Test Front to Back 1 2 3 4 5 6 dry 105+ 105- 115+ 120- 115+ 120- wet 120 115+ 130 125+ 125 125+ If this test is accurate, then my rings and/or cylinders are worn. That's in the block, right? Does that mean I need a whole new engine? Share this post Link to post Share on other sites
klaykrusher 65 Posted July 31, 2011 Maybe time for a..........HEMI?!! Share this post Link to post Share on other sites
dzJeepChic 2,897 Posted August 1, 2011 Maybe time for a..........HEMI?!! A lot of people are going to Hemi - it's pretty popular with the JK group. If we need to put in a new engine I want one as close to OEM stock as I can get to reduce the impact of switching it out... d Share this post Link to post Share on other sites
K7VZ 19 Posted August 1, 2011 Go with a diesel swap. Share this post Link to post Share on other sites
PMA4x4 4 Posted August 1, 2011 Sounds like its time for a 4.7 stroker. That's less work then a Hemi. Have a talk with Mario Donovan over at Expedition Portal, he is the owner of Adventure Trailers and did a stroker in his MJ its a OBD I HO so its the same as what you have. the stroker is not much more above a regular rebuild. He also have a huge write-up on his over there too. You can contact Bill Baker at BMI machining they have built Jeep strokers before I am having mine done there. Plus Bill is an XJer. Share this post Link to post Share on other sites
mbuckner 208 Posted August 1, 2011 Is the cooling system holding the correct pressure? Radiator cap holding may be weak ... hose clamp somewhere may need to be tightened down .. On my TJ, a hose clamp had become lose just enough to let it seap pressure and run hot ..... Share this post Link to post Share on other sites
stockjeep 43 Posted August 1, 2011 I really don't think those comp numbers justify a new engine. My old 64 4x4 pickup has a v8 with over 300k with an average of 80 cranking comp with no overheating issues. if your motor does not use oil then if was me I would continue to look for the source of the heating problem. There may be internal issues but the fact that there was no combustion gases in the coolent is a strong indication to me that the problem not a serious internal problem. Share this post Link to post Share on other sites
macinyart 8 Posted August 1, 2011 A lot of people are going to Hemi - it's pretty popular with the JK group. If we need to put in a new engine I want one as close to OEM stock as I can get to reduce the impact of switching it out... d OK, Hemis and diesels are not what D wants? She may be able to get around this with a cylinder bore out and a new set of pistons and a ring job. Like the old "overhaul" on the engine. She could end up with an engine that will give a good compression dry. It would be prudent to make sure the crank shaft is good too. Share this post Link to post Share on other sites
