Broken Camshaft Bearing Caps-Where to go next

[KerrBear]

Good morning from chilly Wisconsin-

I am new to the forum, but have garnered some excellent information over the last few years when it has come to some minor fixes with our 03 Explorer. Unfortunately, this time it's not so minor. :/ I am not really vehicle savvy, but will try my best to use the correct parts terminology.

We are in the midst of winter here in Wisconsin, and have endured some of the coldest weather in almost 20 years. We're not sure if this contributed to the problem or not, but when my husband went out to start the Explorer after work one day, it had low to no oil pressure. He drove it about 2-3 miles to get it into an enclosed area. When he started investigating, he could see something broken down inside of the oil valve cover. He removed the camshaft cover, and found two broken camshaft bearing caps on the passenger side. I checked out the Ford parts website, and see that this is not a part that we can purchase separately from the camshaft (at least not that I could see anyway-no part number). Any advice on how to approach the next step in getting it back on the road? My husband was going to check around at local salvage yards to see if it was feasible to just be able to replace them without buying the whole cam, but I would rather take the advice of a seasoned mechanic or DIY'er about the specifications of the parts. Is it best to replace the whole camshaft, and if so, could we get some information for some in depth instructions that could help him throughout the process?

Fretting our tax return will now be consumed by auto expenses.

 

[2Trux]

If they are what I'm thinking, they are part of the head as they need to be bored to fit the cam. You would either need to get another head with matching caps or get caps from another motor and have a machine shop bore them for your head. I don't think replacing your cam is needed unless it was damaged.
I would take some pics and take them to a machine shop and see what they think.

Compare the price between the machinist and used head and decide. The amount of work either way will be the same for you.

 

[2000StreetRod]

very unusual

I've been on this forum since May 2009 and as I recall your's is the first posted instance of the camshaft bearing caps failing on the SOHC V6 except during camshaft removal or installation. I think the bearing caps are numbered and not position interchangeable. Is it possible someone installed them in the wrong places or tightened them excessively? I wonder if the low oil pressure was due to the broken caps or if the caps broke because of low oil pressure. I spent four winters in North Dakota and highly recommend full synthetic engine oil in that type of climate.

Anyway, I agree with 2Trux's post. There are no bearing inserts for the camshafts. The bearing surface is machined into the head and the cap. A rather poor design in my opinion but there is at least one other equally deficient design in the Cologne SOHC V6. There should be numerous failed engines and heads around the country due to timing chain related failures. It might be possible purchase a couple caps and have a machine shop shave and rebore the caps to match the cam bearings. If you post a parts wanted notice you might get a forum member to send you a couple caps just for shipping and handling costs. Otherwise, you'll have to purchase a head (new or used). It takes a special tool to compress the valve springs enough to remove the cam followers - which should be done before removing or installing a camshaft because the caps break easily. Unfortunately, replacing the head also requires retiming the camshafts which takes another special timing tool kit (OTC 6488). I suspect the machining method would be the least expensive because the camshaft would not have to be removed.

Before spending any money on the engine make sure the crankshaft still rotates with no interference. There's a possibility the timing chain slipped or broke and the pistons struck the valves causing enough pressure on the camshaft for the caps to break.

 

[KerrBear]

Thank you for your responses. After I had posted my initial thread, my husband also randomly mentioned about finding a plastic piece laying inside of the head. Exact location from where it broke off is still unknown (he thinks it may be from the timing chain area). 2000StreetRod, I'm afraid you may be correct, and not knowing what else may have gotten chewed up during the process of these camshaft bearing caps breaking, this is more than likely going to be an expensive fix for labor and a new/used engine.

 

[2000StreetRod]

further investigation

I suggest removing the spark plugs and manually rotating the crankshaft checking for interference. If the valves are bent due to the timing chain slipping or breaking then you'll need a replacement head due to the valves and the broken camshaft bearing caps. With the spark plugs removed the only resistance to rotating the crankshaft will be from the camshaft compressing valve springs. You may also be able to detect a bent valve by inspection with the valve covers removed. If the force piston to valve collision force was great enough to break two camshaft bearing caps there's a chance of a bent connecting rod.

The SOHC is an expensive engine to rebuilt. Parts are not that common and therefore not cheap, special tools are required to compress the valve springs and time the camshafts, and the whole process is labor and skill intensive. If there are significant internal problems with the engine it will be cheaper to purchase a replacement engine from a salvage yard. That reduces labor cost, tools, and skills needed.

If you post a photo of the broken plastic piece it may be possible to identify the source. Do you have 2WD or 4WD? The 4WD models have an additional balance shaft and associated chain tensioner and guide.

 

[KerrBear]

I will definitely attempt to get some pictures tomorrow of the plastic piece. As for a picture of the broken camshaft bearing caps, he has put the cover back on over the camshaft since little critters are looking for any little nook and cranny to build a nest and keep warm in during this never ending cold spell.

 

[KerrBear]

Well... it's been over two months, and the Explorer is still "in the shop" at my in laws. My husband has opted to replace both heads due to the camshaft covers being broken on the passenger side, and not sure where the water came from that was in the drivers side head when he removed the cover. The timing chain guide is the probable culprit for all of this ridiculousness. (Plastic piece of CRAP!!) He was told by Advanced Auto that he needs to buy a whole new kit. Any advice on the best place to purchase? Should they all be replaced if the engine needs to be removed?

 

[2000StreetRod]

SOHC V6 Timing Chain Parts Sources

SOHC V6 Timing Chain Parts Sources

As for replacing them all it makes a difference if you have 2WD or 4WD.

 

[KerrBear]

It is a 4WD.

 

[2000StreetRod]

Rear cassette & balance shaft chain tensioner

If you pull the engine (normally required to replace the rear cassette) as a minimum I would additionally replace the balance shaft chain tensioner which requires removal of the block cradle. Removing the block cradle and aligning it when installing is a real pain working under the vehicle with a 4WD. The left cassette, primary chain tensioner and guide, and the balance shaft chain guide can be replaced with the engine in the vehicle after removing the front timing cover. If there is more than 150K miles on the odometer I would purchase the complete timing kit and replace all of the components.

 

[KerrBear]

The engine has been pulled, both heads replaced, both cassettes replaced, as well as the other two chains on it as well. We have been anxiously waiting for a mechanic that works with my husband that was going to time everything on the engine for him, but seems to be dragging his feet now. The frustration is mounting as it has now been out of commission for almost three months. The new heads did not have the oil bars attached to it, so those have to be put on as well. Since I'm a little more seasoned at using the computer, I'm now on the mission to find instructions/directions for replacing the oil bars correctly and timing the engine. Any links you could direct me to?

 

[KerrBear]

After over 3 months of waiting, the Explorer is finally put back together. It started up perfectly fine and ran for about 20 minutes, but was not driven. When it was shut off, it wouldn't start up again. It turns over perfectly fine, just will not start. Any ideas?

 

[2000StreetRod]

If it weren't for bad luck

As the saying goes: If it weren't for bad luck, you'd have no luck at all.
Did the engine overheat due to air in the block?
Was there oil pressure when the engine was running?
Did the engine run quietly?
Have you checked the basics: fuel, spark, compression?

 

[KerrBear]

After a little more detailed information, it turns out that the Explorer ran great for about 20 minutes and then shut down by itself. Our neighbor has a diagnostic computer/tester, and the codes indicated something with an oxygen sensor (which were just replaced last year). The service engine light came on after the Explorer had been running for a bit. There is spark, and fuel, the only thing they didn't check beforehand was compression.

 

[KerrBear]

Not sure if this would have anything to do with the problem at hand, but figured I'd mention it anyways. My husband said it took a bit for warm heat to blow, which really isn't abnormal to me, because I know it takes forever in the winter time to warm up, but the heat stopped blowing after a little bit of time also. Odd...

 

[2000StreetRod]

insufficient coolant?

Many people damage their rebuilt/reassembled engine because they don't purge the air out of the block before running the engine. The water pump is only pumping air, the engine overheats and blows a head gasket. The loss of heater warm air output could be an indication of insufficient coolant. I always fill the block with coolant up to the thermostat before installing the thermostat. After installing the thermostat, housing cover and upper radiator hose then I fill the radiator. That way I know that there is coolant in the water pump.

I suggest a compression check. Look at the plugs when they're pulled to see if they're wet from coolant. The SOHC V6 is a tricky engine to assemble successfully without experience.

 

[KerrBear]

I will have them do the compression test, and see how that pans out. My brother in law had some concern about the spark plug from #1 cylinder being really wet every time he checked it, but they said it was fuel. They also weren't seeing any coolant in the oil. So we'll see where this takes us.

 

[KerrBear]

Depending on the pass/fail of the compression test, is there a series of preparation steps that should be taken prior to attempting to start the Explorer again?

 

[KerrBear]

HAPPY MOTHER'S DAY TO ME!!!! After checking the spark, fuel, and compression, which all were fine, my husband went back to check the timing. Somehow, when it shut itself down (which I'm still convinced it may have been exactly what you said StreetRod about overheating) the timing was off. Who knew?? At around 3pm on Mother's Day, I received a text saying "It's Alive!" and it's been good to go ever since, even though my husband still crosses his fingers every time he gets in to start it. Thank you so much for all of your excellent information StreetRod! It was extremely helpful during this very stressful, high anxiety timeframe.

 

[2000StreetRod]

Congratulations!

Congratulations on getting the Explorer running again and belated happy Mother's Day! Hopefully, your Explorer will give you many years of dependable service.