2019 Mustang GT idle thudding/knocking, authorized engine replacement

[Dfeeds]

Is there info that shows what weight of oil was being used in the engines that had cylinder wall damage?

I highly doubt cylinder wall damage was caused by using 5W-30 instead of 5W-20. If an engine was that sensitive to oil viscosity it would be destroying itself even on 5W-20 during warm-up until the oil thinned down at operating temperature (200+ F).

I haven't seen any. It's, what, 60 pages long? I think I got to 25 before I started skipping around. I do see there's 9 people that said they were approved a new engine, short or long block, and 3 who had other repairs. Did any of the above chime in at any point on the outcome? I remember bigriver said he didn't want to bother test driving the car after the buyback, but the dealership said the sound was gone.

Sponsored

 

[GT Pony]

Next time I'm on my other computer I'll post up the piston clearance for the Gen2 Coyote. I don't have Gen3 info, but maybe someone reading this thread does and can post it up to see if the piston clearance is tighter or looser, or the same in the Gen3.

Finally had some time to dig up some piston-to-cylinder clearance info on the Gen2 (2015-2017) Coyote. The manual mentions the clearance is before the application of the Grafal skirt coating, but the coating is only 20 microns thick so it really doesn't add much size to the piston max skirt diameter.

Grafal piston coating was invented and patented by Mahle, so it's possible the pistons were made by Mahle for the Coyote.
https://patents.google.com/patent/US20050087166

Gen2 Coyote piston-to-cylinder clearance spec is 0.0010-0.0023". Don't know what the Gen3 (2018+) Coyote is, but I'd think it's very similar. If someone has access to the factory service manual for the Gen3 Coyote please post what you can find.

 

[Dfeeds]

The piston to cylinder clearance may vary depending on the method Ford used to up the compression. That actually gets the gears spinning. I remember hearing a similar noise to the rattle on my old 97, but upon swapping the stock heads to the gt40p heads the sound went away. A quick google search of thinner head gaskets causing more noise led me to a forum post where someone had thinned the gasket but had a weird rattle sound that wasn't a tick (prob similar to what is posted for the 2018/2019). Turned out it had nothing to do with the head gasket but that it was an improperly timed engine. I thought I was searching for one answer, but maybe I found another. I had to, obviously, redo the timing starting with TDC. I wonder, then, if that rattle we all hear is simply a byproduct of the ecu retarding the timing based on whatever factors it's set to do so.

 

[GT Pony]

^^^ If it was a rattle from bad timing and ECU control, I'd think Ford would have discovered that by now and put out an ECU update instead of replacing engines.

 

[Dfeeds]

^^^ If it was a rattle from bad timing and ECU control, I'd think Ford would have discovered that by now and put out an ECU update instead of replacing engines.

Engines are being replaced because of cylinder wall damage caused by piston slap. The timing could not even be a bad thing. I want to know what the rattle is, not the piston slap.

 

[GT Pony]

Engines are being replaced because of cylinder wall damage caused by piston slap. The timing could not even be a bad thing. I want to know what the rattle is, not the piston slap.

If an engine had the rattle and there was cylinder wall damage, and the rattle went away with a new short block, then the rattle was caused my mechanical problems and not by bad ECU programming. If it was caused by the ECU, then it would rattle the same with a new short block. From what I'm reading, a new short block cures the rattle.

 

[Dfeeds]

If an engine had the rattle and there was cylinder wall damage, and the rattle went away with a new short block, then the rattle was caused my mechanical problems and not by bad ECU programming. If it was caused by the ECU, then it would rattle the same with a new short block. From what I'm reading, a new short block cures the rattle.

Does it? The most I read was that it made things quieter. The only instance I saw of the rattle being cured was when bigriver said his dealership said so, but even then he didn't actually confirm it himself.

 

[Dfeeds]

So I'm driving my car and TRYING to enjoy it and convince myself there's not an issue but the power feels very inconsistent. Not terribly so but there is definitely a difference and it sometimes bucks. I'm also getting small puffs of white smoke at idle after being driven for 40 minutes. This car has 550 miles (549.9) on it. I took two new videos of a warm idle from each side (op video is cold idle). The more I listen, the more I think I hear a thud/knock, and there's definitely a tick coming from the passenger side.

Drivers side


Passenger side


This crap is depressing

 

[pro 5.0]

Sounds like a bearing issue, deep knock is always bottom end related. Come on Ford it's a 2019 you think that you would have your shit together after the 2018 problems, I just ordered a 2019 might have been a mistake.

 

[Dfeeds]

Sounds like a bearing issue, deep knock is always bottom end related. Come on Ford it's a 2019 you think that you would have your shit together after the 2018 problems, I just ordered a 2019 might have been a mistake.

I agree, hence my trying to convince myself that I didn't have an issue. If the 2018 had so many then the 2019 surely would have had the fix... but, looking at older posts, a lot of them are within the last several months and after the 2019 was in production so who knows. Maybe Ford just figured it was within an acceptable margin of defects. Someone posted saying that they had their block replaced and Ford made design changes so maybe you'll be okay.

 

[pro 5.0]

What is the production date on your car and does the engine have a build date ? If your car has an issue and it's a 2019 what motors is Ford using to replace the defective engines with on older 2018's. Makes no sense they replace motors on 2018's and solve the issues yet your 2019 has issues.

 

[Dfeeds]

What is the production date on your car and does the engine have a build date ? If your car has an issue and it's a 2019 what motors is Ford using to replace the defective engines with on older 2018's. Makes no sense they replace motors on 2018's and solve the issues yet your 2019 has issues.

If memory serves, the engine build date was in july, so before some of the posted replacements. It definitely doesn't make sense that this issue took a year to surface when it's noticeable with very few miles. Some people here have a couple thousand miles but I was hearing the rattle at 4 miles. I just thought it was normal... there's a sister car to mine that may still be on the lot but I'd say it's safe to assume it may have the same issue.

There's a chance that, up until very recently, defective engines were getting replaced with defective engines. I don't think it's hard or expensive for ford to produce a short block, from what I read about their v8 production, so throwing new shortblocks at it may be their easier option.

 

[pro 5.0]

When I was at the dealer I drove a 2019 A10 for about 30 min's then I parked it and let it idle for about 10 min's, the motor was very quiet no abnormal sounds of any kind. The scary part is that same car could develop problems after the first oil change and have a ticking or piston slap, you just have no clue what issues are going to pop up. The whole point of buying new is to have piece of mind may not be the case here, in your case you heard the sound at 4 miles but unfortunately it was your problem once you took ownership. Hopefully Ford replaces the engine without any fuss any idea what changes were made to the block in the revision.

 

[Dfeeds]

When I was at the dealer I drove a 2019 A10 for about 30 min's then I parked it and let it idle for about 10 min's, the motor was very quiet no abnormal sounds of any kind. The scary part is that same car could develop problems after the first oil change and have a ticking or piston slap, you just have no clue what issues are going to pop up. The whole point of buying new is to have piece of mind may not be the case here, in your case you heard the sound at 4 miles but unfortunately it was your problem once you took ownership. Hopefully Ford replaces the engine without any fuss any idea what changes were made to the block in the revision.

Not sure. https://www.mustang6g.com/forums/threads/bbq-tick-solved.111085/ hints at it and https://www.mustang6g.com/forums/threads/2018-mustang-gt-5-0-issues.103797/

Bearing issues in the crankshaft and rods make sense. The rattle sound I heard is almost identical to a sound I heard on my old 97 with a 5.0 from a 95 GT. It went away after a head swap, but soon later it came back and then was followed by a nasty knock that was unmistakably a rod knock. So I wonder if that sound/rattle is a failing bearing or something. That could, in turn, cause piston slap to develop. Although I think I've also read speculation that the new cylinder liners are defective. Who knows. Between the clutch, transmission fork issues, engine noises... these last few years seem to be a huge mess. I can't help but laugh to myself at the irony that I lost my old Mustang to a rod bearing, and may have the a very similar issue on my brand new replacement Mustang.

I also was talking to a buddy I work with who said his wife works for a company that manufactures parts for a lot of the major car brands. He said she refuses to even drive a Ford because they always skimp and go for the worst quality parts one can get. Hear say, but hard to argue from where I stand.

 

[pro 5.0]

I think people get mixed up with bearing problems and piston slap one has nothing to do with the other. Piston to wall clearance only changes with higher mileage taper in the cylinder, if it's set too tight from the beginning you will get score marks in the bores. When the engine is cold you may hear what sounds like a diesel sound coming from the intake manifold then as the car warms up the piston expands and the noise goes away that is piston slap. Since these engine use a cast silicone based piston the piston to wall clearance will be tighter around .002 you shouldn't hear any piston slap with that clearance hence the use of that piston material is to keep the engine quite. A forged piston will have a greater clearance in an OE application that would be around .003 - .004 in a race motor that could increase to .006 - .008 depending on the intended use of the engine. The spray in lining has been used in the GT 500 since 2011 or 2012 and is also used in the GT 350 I doubt that there is any problem with that process, I believe that the ticking problems are caused by poor clearances in the motor during assembly whether it be bearing clearance or connecting rod side clearance. If there is a bearing clearance problem cutting open the oil filter should reveal copper bearing material, however excessive connecting rod side clearance may not show any signs of trouble other than the typewriter tick. If the connecting rod side clearance is an issue a thicker oil may not completely solve the problem but it should make the sound less noticeable, if Ford can't assemble a new motor with the correct clearances then they should give the customer a cash incentive of 8K when purchasing a mustang so that they can rebuild the engines themselves and know it's done correctly.

Sponsored