EngineBuilding
Ford SOHC 4.0 timing chain guide failure, is engine still reusable?
So in good old ford fashion, the timing chain guides broke on my 2003 ranger 4.0. Truck was still running fine without any rattle, timing has not jumped. I only noticed it failed when I dropped the oil pan and found the guides in it. The broken guides don’t concern me too much because they are replaceable. What does concern me is this grinded down bolt. The guide is supposed to be held in place by that bolt, but since it broke off, the chain was riding along the bolt. Did not notice any significant metal shavings in the pan or oil filter, camshafts are still mint. I still need to check the rod bearings. Based on how much metal has been grinded off this bolt, would you still reuse this motor?
Discussion
Yes reusable.
Is it the front chain guide or the rear chain guide?
Thank you. This is the rear chain guide. Front chain guide also failed but not as bad as the rear.
I was a gasoline drivability senior master technician at Ford(technicians are specialized to a single field). I hated heavy line work, but I hated working on these in the vehicle even worse. I'd often have to repair a previous bad install of the rear tensioner. I'd pull the engine to lesson the frustration. Just my 2 cents.
Sorry I should mention the engine is already out. I meant to upload more pictures but either something went wrong in the upload or I forgot to attach them. I’m wondering how often do you see the chain grind that bolt down?
Cool then get the OTC kit and get to work. Good job👍
Yes I have the OTC kit. I was so adamant on not using it at first, but I found it for very cheap on marketplace so had to grab it lol.
You'll be glad you got it.
I think i will too. Seems ford made this engine way more complicated than it needs to be as a way of saving a few dollars. Even my benzes have much simpler and more effective timing setups.
Speculation of engine design is a bad idea. Just a heads up. Personally I try to only speak on things I know.
I worked for Ford for 17 years and retired a Senior Master Automotive and Diesel Technician. Knowledge is power.
Well I am not wrong. I am an engineer, I can understand the decisions they made. Both cylinder heads are cast the same, which saves them a lot of money. Of course though, because of this they needed to flip one around for the spark plugs and exhaust manifold to be on the outside, which is why there is a jack shaft and rear timing chain. If the two cylinder heads were different, there would be only one timing chain + the occasional balance shaft. But they were under lots of pressure to make an affordable truck/maximize profit.
If it hadn't skipped teeth / valve timing -and avoided bent valves , after further inspection as you say -Bearing/ s. condition ,No damage and good oil pressure ,Doing the job yourself ,you and your skill and knowledge,should answer your question , How is the rest of the engine ,How many miles on it , Do you take a punt ,Or do you not