[2003_ford_taurus]

Had a P0174 code thrown, checked under the hood and noticed the coolant reservoir had cracked and was leaking, assumed a head gasket had gone, weak flow on coolant return to reservoir but no obvious bubbling. Coolant drained out clean, oil wasn't milky or bubbly. No obvious moisture on spark plugs or oil cap. There was some oily sludge like build up on the valve covers. Darker oil (burnt?) on the lower, not copper colored. Spark plugs looked whitish. Elbow coming off the PCV/crank case was dry rot/perhaps overheated and throwing oil from around the PCV it looks. Pulled upper and lower manifolds. Some speckled pitting on mating surfaces on top side of lower manifold. Underside of lower going in to cylinder head assemblies were having pretty bad pitting/corrosion on the coolant channels, there was also precipitate gunk (no signs of oil) in the coolant channels passenger side on the lower manifold. I noticed the T50 bots holding it down seemed to have heated on the ends (passenger and driver side) more than those in the center, and the mating surfaces are cleaner in the center.

My best guess is it had dex cool (green?) at some point, was swapped or gold was added, this crashed out and gelled clogging the cooling system or slowing the flow. This then caused pressure to build blowing out the coolant reservoir, or caused a gasket failure though I'm not sure I'm seeing a fully blown head gasket. There are signs of coolant leakage on the lower gaskets coming from the cylinder head assembly. I'm still pulling to get down to the heads (don't have the tools atm to pull the studs on the power steering cradle), but I got a glance at the left (front most) head gasket and it doesn't look totally blown out. No other codes. I'm guessing the coolant system got clogged, then it worked sup-optimal, burnt out the PCV elbow and finally threw a code.

My question is if I can actually clean out the coolant system to any degree. Obviously I can replace some hoses, i was thinking of trying to blow out some runs with compressed air before reassembly, but that doesn't really account for how glue like this "stuff" is, I'm having to scrape to clean out the channel on the lower manifold. There's significant corrosion on the passenger side coolant channels on the cylinder head assembly, both left and right. I'm tempted to creatively engineer this, clean out the pittings and JB weld, sand it down, reassemble with new gaskets, then try and clean out the coolant system, but if it won't solvate in water I'm not sure how much chance I have to really get the old gelled material out.

I just want to get a little more life out of it, is there a product or approach that could clean out the coolant system? It's never thrown a warning to the dash it was overheating. I did have a low oil warning driving around town, which I quickly topped off.

 

[ice445]

Hmm, more investigation is warranted. The head gasket leak that's external that you're seeing is probably from the timing cover coolant jacket. Is this the 3.0 OHV engine or does it say Duratec on it? Can you show us some pictures of the spark plugs? Whitish residue can sometimes be coolant burning. Does the exhaust smell syrupy, especially on cold starts?

Cleaning gelled coolant sounds unfun, Probably best to try and blow pressurized water through the passages to get most of it out.

 

[2003_ford_taurus]

Hmm, more investigation is warranted. The head gasket leak that's external that you're seeing is probably from the timing cover coolant jacket. Is this the 3.0 OHV engine or does it say Duratec on it? Can you show us some pictures of the spark plugs? Whitish residue can sometimes be coolant burning. Does the exhaust smell syrupy, especially on cold starts?

Haven't noticed white smoke on start or a smell, does seem to have a rough idle, with a bit of a putt-putt or stutter when I put my hand on the pipe (cold obv). Pulled the left (front most) head assembly and took some pics, this was the bank that was throwing the code though that might be from a leak on the LIM which had pitting out of the coolant channel on the timing cover side that appeared to be escaping past the gasket (whitish residue around the surface of the old LIM gasket). I'm holding off on the rear until I get a better idea because it's a pain to get out with the exhaust down pipe and heat shield, nevermind I'll pull the timing cover if I do that as well.

Got pics of the left block, gasket, head assembly, and spark plugs. The old gasket seemed pretty warn with potential seepage, failure on the coolant channels (rusted areas). It peeled off and adhered to both the block and the assembly so I'll have to clean it out, I was thinking a brass brush. I'm not seeing obvious pitting though as on the LIM.

It's a 3.0L V6 OHV Vulcan I believe on a 2003 SES with ~95k. I'm thinking if it holds up getting a replacement LIM, redoing the timing and head gaskets, and checking the timing chain tension while I'm in there.

http://imgur.com/a/EpYLyAB

 

[sheila]

^ Fram, the "orange can of doom". lol.

 

[2003_ford_taurus]

^ Fram, the "orange can of doom". lol.

I would prefer not to get into a silly holy war about oil filters, can't say I've particularly looked into the issue, I just like the textured grip. Pretty sure my engine troubles are common complaints on the taurus regardless.

 

[ice445]

Definitely needed head gaskets. Nothing really bad but I see some clean spots on the pistons, cracks and corrosion around several water jackets. Spark plugs look pretty clean as well. Do the rear bank when you have the time, you don't want to repeat this twice when the rear is probably just as bad, if not worse. Some of this is evidence of a lean running motor though which makes sense if you had a long term vacuum leak. Definitely get those heads checked for valve leakage while you have them off.

In my experience you won't really get white smoke with these cars, even with pretty bad coolant consumption. I think the three cats cleans it up enough. What you will get however is exhaust that smells like pancake syrup, and rough idle on cold starts.

 

[Jeff K]

Also, coolant going thru the exhaust tends to kill 02 sensors. May want to check their switching rate and voltage swing. Even if those 2 tests check out, coolant thru the exhaust can cause a chemical shift that causes the 02 sensors to incorrectly read the air-fuel ratio.