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I have a 2003 EB Expedition with the 5.4L with just over 200k miles. About a year ago it started leaking a little oil on the passenger side that would drip on the exhaust and burn; never left puddles just an annoying smell. It appeared to be coming from the head gasket, not the valve cover so I left it alone. Back in May it started leaking coolant on the passenger side too. All hoses were fine so I figured the head gasket completely gave out and it was time for new ones. So I bought a complete gasket kit and a timing chain set since they needed to come off anyway. The job went fine. Refilled the coolant, took it for a short drive, and topped it off. Took it for a longer drive and it started to overheat. I ended up having to bleed off a bunch of air and refill it. Then everything was fine. Took it to Seattle and back (200+ miles each way); no issues. Beginning of June it started leaking coolant again. I figured it had to be something else so I bypassed the heater cores and the leak was gone. OK, so now I start planning to replace the front core, but the engine would overheat sometimes after about 30-40 minutes of driving. But it wouldn't happen every time. The t-stat wasn’t very old, but I changed it anyway. No change, still randomly overheating. I changed the reservoir cap and no change again.
Then two weeks ago, the radiator blew out before the engine temp spiked. Temp spiked and the CHT sensor went off putting the car in limp mode. Got it home and filled it with water to cool the engine. So now the radiator is shot as water just pours out the top tank; tank looks fine but the seal is gone. My immediate thought was that one of the head gaskets failed and pumped exhaust gases into the cooling system. So last weekend I did a compression test (cold engine since I can’t really run it) and all cylinders checked out fine: 170-190 psi on all cylinders.
So what else could cause enough pressure to build up in the cooling system to cause this? I hesitate to spend $200 on a new radiator just to ruin it. I probably forgot something, but that's all I can remember for now. Any help trouble shooting this would be appreciated.
The oil side is higher pressure than the water side so did you have any oily sludge in the anti freeze at any time? If not you may have just had a radiator that blew out. Your overflow cap should never let the pressure get above a certain point so a spike in pressure would be really odd unless you were revving the engine downshifting on the interstate maybe. You may of had a partially blocked radiator causing cooling issues and backpressure issues. Since the leak down test looked good I'd go ahead and replace the radiator and make sure to work out all the air bubbles with the typical antifreeze/water mix. Running water through the engine while hot may have done some warping but if the leak down was good I hope your okay. Should have just let it cool down on its own. Cool water and hot motor are never a good thing.
Well, you can put the new radiator in it and leave the reservoir cap off and see if you get a lot of air bubbles blowing off in the reservoir without destroying it. When I've had blown head gaskets in the past I always got exhaust soot in the coolant and it showed up in the reservoir. Are you seeing any of that ? Do you think your old radiator had a blockage in it that might've caused the failure and random overheating? Is your cooling fan clutch in good shape ? The reservoir cap is a 16 lb relief cap, so it shouldn't be enough to damage the radiator. Get a new cap when you get the new radiator just to be sure it's in good shape.
The oil side is higher pressure than the water side so did you have any oily sludge in the anti freeze at any time? If not you may have just had a radiator that blew out. Your overflow cap should never let the pressure get above a certain point so a spike in pressure would be really odd unless you were revving the engine downshifting on the interstate maybe. You may of had a partially blocked radiator causing cooling issues and backpressure issues. Since the leak down test looked good I'd go ahead and replace the radiator and make sure to work out all the air bubbles with the typical antifreeze/water mix. Running water through the engine while hot may have done some warping but if the leak down was good I hope your okay. Should have just let it cool down on its own. Cool water and hot motor are never a good thing.
You're right about the cold water. That thought the same thing after I had already done it. However, there was still coolant in the engine and radiator up to the top tank; so it should have mixed with hot coolant fairly quickly, I hope. I have not seen any mixing of fluids anywhere.
Originally Posted by Hamfisted
Well, you can put the new radiator in it and leave the reservoir cap off and see if you get a lot of air bubbles blowing off in the reservoir without destroying it. When I've had blown head gaskets in the past I always got exhaust soot in the coolant and it showed up in the reservoir. Are you seeing any of that ? Do you think your old radiator had a blockage in it that might've caused the failure and random overheating? Is your cooling fan clutch in good shape ? The reservoir cap is a 16 lb relief cap, so it shouldn't be enough to damage the radiator. Get a new cap when you get the new radiator just to be sure it's in good shape.
I have yet to remove the old radiator, so I don't know about blockage. I have not checked the fan clutch, but they are non-functional at 70 mph anyway. I already replaced the reservoir cap and it made no difference.
Even with a blockage in the radiator, the water pump won't over-pressurize it. The pressure (when all is well) comes from heat expansion.
I agree with the others above, put a new radiator in it and keep the cap off for testing etc.
I have a suspicion that the old radiator was going out anyways, and the random overheating was air pockets being allowed in by the leak in the radiator.
I've installed a couple of Spectras and had zero issues in probably 30,000 miles and three years so far. I get the eebie jeebies about these weird brands, but they're about the only choice at a near-reasonable price these days.
That was probably allowing air to pull in during cooldown. If it was the top then putting in cool water while running should have mixed enough to have no issues with warping (we all hope). When my work van radiator went out I put in a Spectre from NAPA. Many miles and my only issue is oil cooler line o-rings going bad. Probably 100k on it so far.
Forgot to update this. So I ordered the Spectra Premium radiator above from Skyblue Auto Parts 2 on Amazon. Turns out that is just a front for RockAuto and they actually sent me the cheap TYC radiator instead. So after waiting a week and a half for that one, I had to return it and re-order the same radiator directly from Amazon (same link above but cost more). It should be here today. In the meantime I did get the front heater core replaced. What a pain in the a$$ that is! Sometimes I really want to slap a Ford designer upside the head with a baseball bat! It really isn't that hard to get to the heater core or loosen the heater box from the firewall, but because of the way they routed the AC lines, you can't pull the box away from the firewall. And there was no way I was going to open the AC system just for the heater core. I would have cut the firewall first. I was able to get it in by bending the supply lines slightly and work one in at a time.
Glad to hear you're getting this close resolved, but it's frustrating all the hassle replacing the heater core. The information on AllData is woefully incomplete, but they do show it to be a 7.8 hour job, so sounds like a real PITA.
Just out of curiosity, why did you return the TYC unit? I'm not sure about Spectra, but TYC is an OEM tier 1 supplier that makes parts that go into new cars. I wouldn't be opposed to a radiator from them.
Based on the searching I did, the TYC was listed as an economy replacement while the Spectra was listed as standard/OEM. Now that I have the Spectra, I'm glad that I did. The quality of the plastic tanks appears to be much better than the TYC's. Of course that's just my opinion based on visual appearance.
Well, I got the correct radiator last week and installed it without the t-stat. Filled it with water and radiator flush only. It's been driving just fine. I'll drain it this weekend and depending on how nasty it looks, I'll flush it again or fill it with coolant. Any recommended brands/types (green vs yellow)? I've dumped too much money into this pit, so I'm not spending $31/gal for Motorcraft.
BTW, I cut the old radiator in half and what I found was pretty nasty.
I would use Motorcraft Gold or Zerex G-05 ( Advanced Auto... NAPA...) . You can get the Motorcraft Gold premix on Amazon for about $22 a gallon shipped. Using the wrong coolant may lead to heater core failures as well as other cooling system issues.
However, there was still coolant in the engine and radiator up to the top tank; so it should have mixed with hot coolant fairly quickly, I hope. I have not seen any mixing of fluids anywhere.
