2018 CX-5 Oil Leak? Is this TSB for Tensioner?

There’s very thick and very minimum amount of oil inside of belt tensioner. The leak from tensioner usually will only be an oil film coated on the tensioner itself only. You won’t see any oil dripping to any other areas. Here’s what my leaky belt tensioner looks like on my 2016 CX-5 at 41,150 miles:

View attachment 298639

Make sure to show the TSB to your Mazda dealer when you take your 2018 CX-5 Sport in for timing chain cover leak.
Thank you, yeah my belt tensioner looks pretty clean so I figure it's gotta be the timing chain cover. It's a shame this still seems to be a common problem for this car. I've got the TSB printed out, just hoping the dealer doesn't try to give me the run around.
 
Thank you, yeah my belt tensioner looks pretty clean so I figure it's gotta be the timing chain cover. It's a shame this still seems to be a common problem for this car. I've got the TSB printed out, just hoping the dealer doesn't try to give me the run around.
On SkyActiv-G 4-cylinders Mazda splits usually one-piece cylinder block into 2 pieces. And it’d be a challenge to make sure leaks won’t be developed in the long run. IMO this’s another example that Mazda is trying too hard to be different from others. Some are good but some are bad.

So, the block is actually 3 pieces- head, cylinder block, and lower cylinder block, with the timing chain cover connected to both bottom pieces. Yikes! I'm surprised this thing doesn't have more leak problems.
 
Forgot to update. The dealer used the TSB to fix the leak. They didn't have to drop the engine. Driven about 200 miles since, no sign of leak, but guessing it's too early to tell right now. So far so good though.
Good to read it's worked out ok for you, so far anyway. With sections of the gasket being inaccessible, this repair is a PITA to monitor, even with an inspection camera. And those panels underneath the vehicle could catch and retain quite a bit of oil before an external leak shows up. But no point in worrying about it, because they're on the hook for any subsequent issues, and hopefully they did everything correctly and you'll never have to revisit this again.

Do you see a number of hours listed for this repair on your paperwork? If so, that would be the 'book' amount of time that Mazda Corporate reimburses the dealer for the warranty work. The auto dealer techs who post on these forums regularly complain that these flat rates are quite a bit too low across the board, and I'm always interested to know what the numbers actually are.
 
Probably this. comes from the tsb.
so aprox 4 hrs from what I see.


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Probably this. comes from the tsb.
so aprox 4 hrs from what I see. ....

Yes, that probably what Mazda pays for this job, and about what I'd expect, based on other, related information. Being a DIYer, I'm always interested in these things, trying to figure out if the automaker 'book' hours are really as bad as the techs say they are.

On one hand, I'd expect that if someone did this job frequently (something like 2-3 per week), then they would become very fast at it, and under 4 hours doesn't seem unreasonable at all. But on the other (and far more important) hand, everyone here would hope that they're actually doing very few of these jobs. And if that's the case, then I wouldn't expect the typical tech to be so familiar with the job that the movement becomes automatic, based on a high number of reps.

I'm sure that most other folks here don't care about stuff like this, but I don't play video games, so I have to find stupid things such as this to keep my mind occupied ;)
 
There’s very thick and very minimum amount of oil inside of belt tensioner. The leak from tensioner usually will only be an oil film coated on the tensioner itself only. You won’t see any oil dripping to any other areas. Here’s what my leaky belt tensioner looks like on my 2016 CX-5 at 41,150 miles:

View attachment 298639

Make sure to show the TSB to your Mazda dealer when you take your 2018 CX-5 Sport in for timing chain cover leak.
Just got my car back from the dealer today, they confirmed the front cover leak and resealed the gasket. They mentioned they've done this job a few times before on other 2018's so we'll see how it holds up. Unfortunately I noticed they damaged a cable though, that goes to what I think is the crankshaft position sensor (pic attached). Looks like it melted through the insulation, so I'm guessing what happened is they forgot to secure that clip before they took it for a test drive and it contacted a hot part of the engine. Then they noticed it afterwards, clipped it in, and hoped I wouldn't notice. Bastards. Luckily I have pictures from before I took it in that show the cable in good condition so I can prove it's their fault. So back to the dealer next week. I'm half tempted to tell them to replace it with a new harness since I don't trust whatever splice repair job they might do to hold up over time, but I'm not sure how feasible that would be.
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Just got my car back from the dealer today, they confirmed the front cover leak and resealed the gasket. They mentioned they've done this job a few times before on other 2018's so we'll see how it holds up. Unfortunately I noticed they damaged a cable though, that goes to what I think is the crankshaft position sensor (pic attached). Looks like it melted through the insulation, so I'm guessing what happened is they forgot to secure that clip before they took it for a test drive and it contacted a hot part of the engine. Then they noticed it afterwards, clipped it in, and hoped I wouldn't notice. Bastards. Luckily I have pictures from before I took it in that show the cable in good condition so I can prove it's their fault. So back to the dealer next week. I'm half tempted to tell them to replace it with a new harness since I don't trust whatever splice repair job they might do to hold up over time, but I'm not sure how feasible that would be.
View attachment 299148
Thanks for the update. Unfortunately not a good result though from dealer’s work. I’d watch the leak for a while due to the sloppy job evidenced by the findings in the picture.
 
Yet another of many examples why I have such a low opinion of stealership service. Although an owner normally wouldn't be able to have input to how a repair will be done, IMO this might be an exception to that. This is clearly a case of damage to your vehicle, caused by a mistake by the tech, which I believe entitles you to insist on a harness replacement instead of a patch job. You can argue that no repair is going to have the integrity of the factory harness, and could become a point of failure in the future.

OTOH, they might not even trust the tech to repair it, and tell him/her to install a new harness anyway. And +1 to what yrwei52 wrote above, that you'll need to monitoring for leaks for a while, because it might take a long time to be able to actually see a really slow weep in one of the locations that are difficult to access.
 
Is that exposed copper in the pic?

I wonder if it got into the belt somehow.
 
⋯ This is clearly a case of damage to your vehicle, caused by a mistake by the tech, which I believe entitles you to insist on a harnessu replacement instead of a patch job. You can argue that no repair is going to have the integrity of the factory harness, and could become a point of failure in the future.
Yes, if it was me I’d call and sent the picture to service manager and demand the harness replacement.
 
Talked to the dealer this morning and sent them the pictures, and much to my surprise they immediately agreed to replace the entire engine harness without giving me any hassle at all. They're getting the harness overnighted and should have the replacement done by Friday. Certainly still have trust issues with their mechanics but have to admit I'm impressed with how the management team is handling it so far. Gonna tell them to have a senior mechanic perform the job or at least oversee it and thoroughly inspect everything. I'll report back if there's any further issues and like y'all have mentioned I'll definitely keep a close eye on if the leak returns.
 
I am currently having this issue too. Oil leaking at the same location as yours. My 19 CX-5 GT is only 22K miles, this sucks!
 
OP, can you provide me the fix that they performed on your vehicle please? If you still have the invoice they gave you, Any TSB involved, please provide bulletin # if possible. So, they can specifically look into the problem quickly. I am bringing in my car tomorrow. Thanks in advanced!
 
Just want to update and share what I experienced. My 19 CX5 GT had a rubber burning smell and smoke went into the cabin. Next day I jacked up and checked to locate the oil leaks. It appears oil leaking all over the timing chain/belt cover area. I was able to drive to the dealership and drop off. The service dept. staffs gave me the look of what the hell is going on with my car. Smoke all over the hood area when I was in the service dept.

Waited for an hour of inspection, service advisor came over and told me that the cylinder head need to be replace due to leaks from cylinder #3. I asked if this is common issue for Cx-5, he said he saw certain number of CX-5s been getting cylinder head replaced due to this same issue. This is a TSB fix (TSB #SA-031-21) only if you have this oil leaks. I think Mazda should having a recall for those who have cylinder deactivation for their model years. They set me up a loaner vehicle to drive while the car is waiting for parts and getting the cylinder head replace. I assume it might take up to 1-1.5 months. I believed cylinder deactivation engine will cause this oil leaks, it just a matter of time when its going to happen. GL y'all!
 
Can't believe Mazda is betting the farm on CD. There's very little upside, if the mpg increase was 4-6 mpg that would be something but from all I've read it's more like 0-1 mpg.
Glad I have a turbo and a 16 that's Non-CD.
 
Just want to update and share what I experienced. My 19 CX5 GT had a rubber burning smell and smoke went into the cabin. Next day I jacked up and checked to locate the oil leaks. It appears oil leaking all over the timing chain/belt cover area. I was able to drive to the dealership and drop off. The service dept. staffs gave me the look of what the hell is going on with my car. Smoke all over the hood area when I was in the service dept.

Waited for an hour of inspection, service advisor came over and told me that the cylinder head need to be replace due to leaks from cylinder #3. I asked if this is common issue for Cx-5, he said he saw certain number of CX-5s been getting cylinder head replaced due to this same issue. This is a TSB fix (TSB #SA-031-21) only if you have this oil leaks. I think Mazda should having a recall for those who have cylinder deactivation for their model years. They set me up a loaner vehicle to drive while the car is waiting for parts and getting the cylinder head replace. I assume it might take up to 1-1.5 months. I believed cylinder deactivation engine will cause this oil leaks, it just a matter of time when its going to happen. GL y'all!
So your problem is not related to leaky belt tensioner and a lot more severe than we thought. And your post should get referenced by a cylinder deactivation related topic. This Service Alert #SA-031-21 was issued on 5/6/2021 by Mazda for 2019 CX-5, but NHTSA has not posted this SA document yet and there’s no detailed info from the Internet.

A new cylinder head assembly for service parts has been newly established for SKYACTIV-G 2.5 with cylinder deactivation when replacement is needed. Valves, valve springs, valve spring seats, and cotters (IN/EX) are included in the new assem

I seem to remember the same wording “a new cylinder head assembly for service parts has been newly established” mentioned in another cylinder deactivation related TSB which basically created a new part number with pre-assembled cylinder head with valves to save the installation time. Not sure if there’s any modification on cylinder head design, or anything else to prevent this failure happening in the future. If not, this means the same problem could be happening again.

This’s a continuation of problems on SkyActiv-G 2.5L with cylinder deactivation. I’m glad I canceled my purchase on a 2018 CX-5 GT once I learned Mazda would feature CD on the 2.5L for merely 0 ~1 EPA MPG gain. And I’ll continue to suggest don’t buy any cars with problematic cylinder deactivation if you plan to keep your vehicle for long term.

Now, any new development on coolant leak issue which requires engine replacement on 2.5T? It seems to be happening after 3 ~ 5 years of the engine service?

2.5T Coolant Leak/Engine Replacement. What can be done to prevent?
 
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Can't believe Mazda is betting the farm on CD. There's very little upside, if the mpg increase was 4-6 mpg that would be something but from all I've read it's more like 0-1 mpg.
Glad I have a turbo and a 16 that's Non-CD.
Agreed on cylinder deactivation part. But your 2.5T isn’t immune to the problems. Now the coolant leak problem on 2.5T which requires engine replacement just started popping up on early 2016 ~ 2018 CX-9’s. Eventually we’ll see it on CX-5 which only started featuring the engine in 2019 MY. See the link in my previous post.
 
... I believed cylinder deactivation engine will cause this oil leaks, it just a matter of time when its going to happen. ...
Although I have a very negative opinion of cylinder deactivation, based on multiple other issues, I've seen nothing which connects CD to an oil leak. Information from other threads and sources indicates that there were a batch of heads produced which have manufacturing defects, and are the root cause of some external oil leaks.

If you ask the service advisor who mentioned the cylinder #3 leak, perhaps he/she would confirm a defective cylinder head on your vehicle.
 
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