New to the 4.0 sohc

[Rosco P]

Hello all, I have two 2nd gen explorers one is a '98 Eddie Bauer with a 5.0 and 59k original miles the other is a '97 Eddie Bauer with the 4.0 sohc German engine which I'm finding I hate!! This 4.0 has only 66k and has timing chain noise how ridiculous! I just pulled the upper intake and replaced the left hydrolic tensioner, now after reading in this forum I see that I need the oil restrictor in the gallery as well..it still has noise that comes and goes driving me crazy, I used a cloyes part and will do the rear soon..but really even being old only 66k Noise?? I've been a mechanic 33 years and I'm not impressed with German engineering! My 5.0 rips up the road and I know I can trust it but this 4.0 POS.. IDK..venting... Is it worth going to the trouble to r/r again just for the restrictor check valve? Seems like the noise is left upper chain like everyone else's..

 

[koda2000]

Welcome to the world of the Ford 4.0L SOHC V6.

The front tensioner is not the problem unless it only rattles at startup. Even then and with the oil restrictor it will still make noise. The bigger problem is that the t/c guides are make largely of plastic and they break. If you remove the lower oil pan you'll probably find broken pieces of tan plastic around the oil pickup. These pieces can and do eventually block the pickup and you lose oil pressure to boot.

Replacing the timing chain components (front and rear) requires engine or at least trans removal. Even after repairs, unless you add a pre-oiler it's only a matter of time before the tc death rattle returns. It's just a poor design. Adding a pre-oiler also eliminates the annoying SOHC starting flare.

 

[Rosco P]

Welcome to the world of the Ford 4.0L SOHC V6.

The front tensioner is not the problem unless it only rattles at startup. Even then and with the oil restrictor it will still make noise. The bigger problem is that the t/c guides are make largely of plastic and they break. If you remove the lower oil pan you'll probably find broken pieces of tan plastic around the oil pickup. These pieces can and do eventually block the pickup and you lose oil pressure to boot.

Replacing the timing chain components (front and rear) requires engine or at least trans removal. Even after repairs, unless you add a pre-oiler it's only a matter of time before the tc death rattle returns. It's just a poor design. Adding a pre-oiler also eliminates the annoying SOHC starting flare.

Welcome to the world of the Ford 4.0L SOHC V6.

The front tensioner is not the problem unless it only rattles at startup. Even then and with the oil restrictor it will still make noise. The bigger problem is that the t/c guides are make largely of plastic and they break. If you remove the lower oil pan you'll probably find broken pieces of tan plastic around the oil pickup. These pieces can and do eventually block the pickup and you lose oil pressure to boot.

Replacing the timing chain components (front and rear) requires engine or at least trans removal. Even after repairs, unless you add a pre-oiler it's only a matter of time before the tc death rattle returns. It's just a poor design. Adding a pre-oiler also eliminates the annoying SOHC starting flare.

Yes thank you I have been reading for the last five days on this subject it's really too bad because the engine seems faultless other than T/C issues, love the 5.0 though what a great engine and the better trans too!

 

[koda2000]

Welcome to the world of the Ford 4.0L SOHC V6.

The front tensioner is not the problem unless it only rattles at startup. Even then and with the oil restrictor it will still make noise. The bigger problem is that the t/c guides are make largely of plastic and they break. If you remove the lower oil pan you'll probably find broken pieces of tan plastic around the oil pickup. These pieces can and do eventually block the pickup and you lose oil pressure to boot.

Replacing the timing chain components (front and rear) requires engine or at least trans removal. Even after repairs, unless you add a pre-oiler it's only a matter of time before the tc death rattle returns. It's just a poor design. Adding a pre-oiler also eliminates the annoying SOHC starting flare.

Yes thank you I have been reading for the last five days on this subject it's really too bad because the engine seems faultless other than T/C issues, love the 5.0 though what a great engine and the better trans too!

I agree the 5.0L is a great engine, of course Ford has had about 40 years to perfect the 302. I currently have four 5.0's and two 4.0 SOHC's in the family. The 5.0's all have 200K+/- and all run great. The '97 SOHC has been rebuilt and has over 260k on it (and still quiet). The plan is to retire this vehicle at the end of the year. The other SOHC has around 190k an makes noise at startup (unless I build oil pressure first).

It's odd that some SOHC's seem to go many miles w/out with t/c problems and maybe this forum typically only hears about the bad ones, but the design requiring engine removal (because Ford wanted to use the same cylinder head on both sides) to repair the guides sucks, as do the hydraulic chain tensioners. IMO, anyone here who believes the SOHC is a good engine design is in denial. The 5.0 makes more power, is way more reliable, gets pretty much the same fuel economy and comes with a more reliable transmission. Too bad the 5.0's weren't available in the Sports and Sport Tracs. The 4 door's should never had the SOHC as an engine choice. If the Sport Trac came with the 5.0 it would be a near perfect vehicle for me.

 

[Tech By Trade]

Lol, I bet you have came across my thread (link in signature). Quality is job 2.

 

[jmvb]

Even after repairs, unless you add a pre-oiler

Phil:

Can you illustrate me what is the pre-oiler?

I'm planning to repair the chains, and I hope do not have this problem anymore

 

[koda2000]

Jose, Read the thread started by david4451 on the pre-oiler subject. Basically it's a 12V electric pump that takes oil from the crankcase and forces it through the vehicle's oil filter and then it pressurizes the engine's oiling system. It's good for the engines bearings, as most wear occurs at cold start, but on the 4.0L SOHC engine the main benefit is that it pumps oil into the hydraulic t/c tensioners. This allow for quiet engine starts (no chains slapping around) and no SOHC starting flare (high RPM as soon as the engine fires) which is designed to get oil into the tensioners as quickly as possible (but typically not quickly enough...). It seems reasonable to assume that this will prolong engine life, as loose timing chains contribute to the engine jumping time, which is most likely to occur at startup. Once the engine jumps time the valves usually smack the pistons, turning your engine into a pile of junk. It's also not uncommon for the front chain to smack a hole in the front of the driver's side valve cover.

Last fall I had sourced most of the parts necessary to build a pre-oiling system for around $200 U.S. 2000streetrod has also put together a pre-oiling system, but at about twice the cost. If I do build the pre-oiling system I'll do it after I replace/rebuild the engine in my '01 ST.

In the meantime, I spin my starter for 8-12 seconds before allowing the engine to start from cold and 4-5 seconds when it's warm. I also use 0W30 Molbil 1 Full Synthetic oil to get the oil pressure up quicker. The result is the same, though a bit hard on the starter motor.

 

[jmvb]

How do you spin your starter and do no start your engine?
Mine start after 1 or 2 sec at crank...

 

[koda2000]

How do you spin your starter and do no start your engine?
Mine start after 1 or 2 sec at crank...

Put the gas pedal to the floor and hold it down. This turns off the fuel injectors and the engine will not fire until you raise your foot.

 

[jmvb]

Great tip, thanks!

 

[Rosco P]

Seems strange the noise comes and goes, maybe a broken guide moves a bit on start and shutoff thus changing chain tension? I saw a video of a guy that drilled and tapped his left hydraulic tensioner and put a long bolt in, he adjusts it while running to quiet the noise.. Seems a little scary to me! I've worked on many vw's and bmw's over the years and don't get me going on Audi's lol! There is no doubt in my mind cloyes or Ford could have made absolutely bullet proof components for this engine! Why not? Oh ya fix and repair = $$$.

I agree the 5.0L is a great engine, of course Ford has had about 40 years to perfect the 302. I currently have four 5.0's and two 4.0 SOHC's in the family. The 5.0's all have 200K+/- and all run great. The '97 SOHC has been rebuilt and has over 260k on it (and still quiet). The plan is to retire this vehicle at the end of the year. The other SOHC has around 190k an makes noise at startup (unless I build oil pressure first).

It's odd that some SOHC's seem to go many miles w/out with t/c problems and maybe this forum typically only hears about the bad ones, but the design requiring engine removal (because Ford wanted to use the same cylinder head on both sides) to repair the guides sucks, as do the hydraulic chain tensioners. IMO, anyone here who believes the SOHC is a good engine design is in denial. The 5.0 makes more power, is way more reliable, gets pretty much the same fuel economy and comes with a more reliable transmission. Too bad the 5.0's weren't available in the Sports and Sport Tracs. The 4 door's should never had the SOHC as an engine choice. If the Sport Trac came with the 5.0 it would be a near perfect vehicle for me.

 

[Rosco P]

Seems strange the noise comes and goes, maybe a broken guide moves a bit on start and shutoff thus changing chain tension? I saw a video of a guy that drilled and tapped his left hydraulic tensioner and put a long bolt in, he adjusts it while running to quiet the noise.. Seems a little scary to me! I've worked on many vw's and bmw's over the years and don't get me going on Audi's lol! There is no doubt in my mind cloyes or Ford could have made absolutely bullet proof components for this engine! Why not? Oh ya fix and repair = $$$.

 

[Rosco P]

It's a good thing they didn't put this engine in passenger aircraft!!

 

[koda2000]

It's a good thing they didn't put this engine in passenger aircraft!!

Yea, it's bad enough we let doctors fly them...

I guess we need to keep in mind that most people that buy or lease new cars don't plan on putting 100th's of thousands miles on them. Back when I bought new vehicles I seldom kept them for much more than 50k-60k miles. From what I've read the 4.0L SOHC engine will often go upwards of 100k before failing (sometimes quite a bit more). With today's 2nd and 3rd hand buyers expecting to be able to get 200k-300k out of a used car's drivetrain, the SOHC is a bad choice. It's really not a matter of IF the timing chains will cause problems but WHEN. Most front wheel drive 4 cylinder engines use a single timing belt, which is fairly easy to change with the engine in the vehicle. If Ford's timing chains were all in the front of the motor, replacing them would not be so expensive, though the weak components would still be an issue.

 

[david4451]

To date my pre-oiler has worked perfectly, with NO rattle at cold startup. Before I fitted the pre-oiler the ST almost always rattled at cold startup. As a majority of people on this forum are enthusiastic about their trucks I wonder how many "normal" drivers have had trucks with the 4l sohc to find one morning it rattles and bangs and the engine is toast!
Ford did a great diservice to its customers by no recall and then not replacing the timing components with reliable parts. IMO the ST is the perfect vehicle for versatility and looks, but if you are a not mechanically biased it is not a wise choice of transport as they age. How I wish they had put the 5l in these trucks!!!!!!!

 

[Rosco P]

To date my pre-oiler has worked perfectly, with NO rattle at cold startup. Before I fitted the pre-oiler the ST almost always rattled at cold startup. As a majority of people on this forum are enthusiastic about their trucks I wonder how many "normal" drivers have had trucks with the 4l sohc to find one morning it rattles and bangs and the engine is toast!
Ford did a great diservice to its customers by no recall and then not replacing the timing components with reliable parts. IMO the ST is the perfect vehicle for versatility and looks, but if you are a not mechanically biased it is not a wise choice of transport as they age. How I wish they had put the 5l in these trucks!!!!!!!

Amen on the 5.0! I see all these videos on YouTube 4.0 sohc noises but hardly anything on what the fix was..guess it's just everyone changing out timing components... Sigh..

 

[david4451]

Yes, your right most are changing out the timing components. As your truck has only 66k miles pre-oiler could give you another "safe" 25k.Provided the is no chain rattle between 2500 to 3000 rpm
As Phil says the damage to timing components is done at startup and the replacing of the hydraulic tensioners will not fix the problem as many have tried.
My ST only has 40k miles on it and the rattle at cold start was making me nuts, hence the pre-oiler.

 

[Rosco P]

Good info thanks! In my local area there is right now about 20 explorers with the sohc VIN # E engine for sale all have between 150k and 190ish k a couple have 220k and one has 270k! I messaged each person about T/C repairs.. Each person had no problems ever or repairs that they could think of, what gives?

 

[david4451]

On this forum it is a major issue with the 4l sohc. I don't want to say they are telling pork pies, but maybe previous owners did the timing chains. Your ex has 66k and mine has 40k and both had/have the rattle at cold start, which will trash the plastic components sooner rather than later and that's low milage for age.
This problem was also recognised by Ford who improved the design on 2002 and later models which is our bad luck!!!!!
I'm a Brit living in Philippines and don't have your luxury of endless engines so I've done the pre-oiler fix. Having said that I will replace all timing components at the first sign of failure and still use the pre-oiler as at 65 I'm sure the truck will out last me once done haha.

 

[Dave98XLT]

My 98 SoHC has 227k miles on the original engine and timing components. However I have used Mobile 1 5w30 since it had 20k on it. There are a few little noises of concern during startup and at idle. However since the overall truck is a rust bucket when and if the engine dies there will be no hard feelings.

Anyway if you are in the position to buy a new or nearly new truck, change all the fluids as recommended, using top quality synthetic lubricants. Engine oil, coolant, tranny fluid, diff and transfer case, power steering and brake fluid.

My SOHC is on the original water pump, and engine seals are still good. The only seals I have had to repair are the power steering rack and the xfer case.