97 Cobra 180,xxx miles I have had the car for a couple months now, was going to put a complete ford timing chain kit in it once I parked it for the winter. Well as always, things never go as planned. I am going to do some more diagnosing this evening, but it seems that one, or both of my timing chain tensioners have went out. It ran fine, I parked it and it sat overnight outside in colder weather. Went to start it this morning and it puttered for a second and died. Now when I turn it over it seems like it has intermittent compression. I am thinking timing chain tensioners. My question is do I most likely have a bent valve considering these are interference? Or should I be okay with installing a new timing chain kit? The engine does have high mileage but it ran great, and did not burn or leak any oil. So it would be worth it to me to fix the problem as long as I don't have a bent valve for something
First things first, lets clear this up a little bit, 180K miles is NOT high mileage for these engines. That thing is still in its prime. Anyway, the only way you would bend valves is if it jumped timing. A collapsed tensioner could cause that. Since you are considering going that far already, pull the cam covers and timing cover, turn the engine by hand and look at the valve springs. Sometimes a bent valve will sit just a tad lower than the rest. You could do a compression check before you tear it all down.
I haven't seen a whole lot of these cobras with over 150k, but I believe you because it has been running great until today lol. Compression check was going to be the first thing I do. I will pull the cam covers tomorrow and inspect all of the valves. I really hope I got lucky and it didn't jump time..
I really think the biggest reason that mustangs don't make high mileage is because people start to modify them and then give up or get in over their head and sell out or let it sit for a bunch of years.
Im calling locked up lash adjuster. And possibly dry valves.....their is 32 of them. If their has been any over due oil changes, black oil, or high than recommended oil weight used ....the lifters will be locked forever untill you manually press the oil out Driven by a tiny bore and more stroke than a 514cuin
I changed the oil as soon as I bought it with 5w20 full synthetic, but this car has been through several owners before me and I really don't have any knowledge if the cars past except for a carfax, so that is a possibility.. When I pulk the cam covers I will check that out
Yeah I agree, my last foxbody I had ran great with 170k. Drove all over the midwest. Sell it, 2 months later it is ragged out on Craigslist with a blown engine and wrecked in the front end lol
When you pull the covers let us know. Extracting the lashers is easy to do. We can walk you through it. By the time you do 32 of them, youll be the expert Driven by a tiny bore and more stroke than a 514cuin
Mine has well over 200,000 miles. Odometer gear broke at around 194,XXX Have you torn it down yet? Check out all possibilities before tearing it down. Have had similar symptoms from just a simple evap problem. I just loosened and re-tightened the gas cap and that solved it. Also some of the symptoms are also caused by fouled plugs.
I did tear it down this evening, but I doubt that is the issue, when turning it over it sounded like it had almost no conpression. I put plugs in it a couple months back when I bought it. Plugs are still good. Tomorrow I am going to do a compression and leakdown test and see where we are from there. Plus I figured it's starting to get cold outside and I was planning on getting a timing chain kit, powder coat the cam covers and intake, and some other little things, so I guess I am starting a little ealier than expected lol
So I haven't had any time at all to mess with the car lately, but I finally found some time to do a compression test today.. at first, all cylinders were only showing about 75 to 90 psi... I then poured a small amount of trans fluid in the cylinders and turned the engine over a few times. Afterwards all cylinders made decent compression, in the 170 range. I also checked to see if the factory timing marks lined up and they do, so it is not out of time. Most of the timing components surprisingly seem to be in good shape,hardly any wear on the cam and crank gears, guides, etc. But I did catch a weak driver side tensioner, so I am planning on ordering new tensioners, but I don't believe that was the issue.. So do you think dry valves was my issue?
Could've been something as simple as thick oil in the tensioner, when is the last time you changed it? I've personally put thousands of miles on my 4.6 and I know they are picky when it comes to oil and viscosity. Has it run since? Any fault codes? Btw if you have a weak tensioner, go ahead and replace the timing chains out while you are at it, the two long ones stretch out a lot!
That's true, I changed the oil about 2500 miles ago w/ 5w20 synthetic. I haven't started it back up yet, I had to order the tensioners from rock auto. The only fault code it had before was an emissions code Sent from my SAMSUNG-SM-G890A using Tapatalk
The chains could be stretched, very possible. ...but I have never heard of chain failure. Usually the trick is to just change out the tentioner arms and guides. The tentioner has the ratchet stop to keep the tentioner from bleeding out to its bottom. If anything the tentioner got locked and the tentioner arm had to much pressure causing premature wear. This is normally the scenario with tentioner failure. Dig in and check it out! Who knows what it might be.
I've inspected pretty much everything, no signs of premature wear, just a weak tensioner. And yes I am just going to replace the tensioner arms and guides, not sure if I'm going to replace the secondary tensioners or not, haven't ever heard of them failing. Sent from my SAMSUNG-SM-G890A using Tapatalk
The iron primary tensioners don't need to be replaced. Take them apart and clean all the old junk out of them then reassemble and install on the car. They create the tension from oil pressure so the tensioner can't be "weak" but it can be working improperly. I just took the tensioners off my wife's truck that has 300k miles on it, cleaned them out, reinstalled and they are working great.
