2013 cold start engine rattle

[DB4MX5]

searched and found nothing related to my issue and that surprised me.
i've had this NC for 8 months and knew about the rattle at that time. But it was a great deal with 50k miles (still under warranty) and with some good service history.
quite a long story- sorry

if the engine soaks outside and it gets down to about 30f the start up has no noise,,, if it sets in the garage at about 60 f it has the start up rattle,,
occasionally i hear a sharp metallic pop when it fires and that is very concerning
tried wix, mazda filter - no diff
0-20 and 5-20 (5-20 is less noisy)
if i hold down the gas and crank for about 5 sec there is no start up noise.

it sound like VVT actuator but i'm not aware of the nc issue.
after it starts its noise free.
the dealer kept it over night but left it outside and said they heard no noisy even though i told them to leave it inside,,, it looks like i have to tell them the issue!!!

anyone seen this issue? thanks for your input.
very nice forum,,
david

[kung fu jesus]

David,

May I suggest taking a video of the issue with your phone (if available), upload it to YouTube and post it here? It would be really helpful to others and for determining the cause/solution. :)

[DB4MX5]

yes, thanks. i have one

[DB4MX5]

searched and found nothing related to my issue and that surprised me.
i've had this NC for 8 months and knew about the rattle at that time. But it was a great deal with 50k miles (still under warranty) and with some good service history.
quite a long story- sorry

if the engine soaks outside and it gets down to about 30f the start up has no noise,,, if it sets in the garage at about 60 f it has the start up rattle,,
occasionally i hear a sharp metallic pop when it fires and that is very concerning
tried wix, mazda filter - no diff
0-20 and 5-20 (5-20 is less noisy)
if i hold down the gas and crank for about 5 sec there is no start up noise.

it sound like VVT actuator but i'm not aware of the nc issue.
after it starts its noise free.
the dealer kept it over night but left it outside and said they heard no noisy even though i told them to leave it inside,,, it looks like i have to tell them the issue!!!

anyone seen this issue? thanks for your input.
very nice forum,,
david

http://youtu.be/pDubRVuaCUU

the sound is actually about 2x what is heard

[DB4MX5]

2013 cold start engine rattle
searched and found nothing related to my issue and that surprised me.
i've had this NC for 8 months and knew about the rattle at that time. But it was a great deal with 50k miles (still under warranty) and with some good service history.
quite a long story- sorry

if the engine soaks outside and it gets down to about 30f the start up has no noise,,, if it sets in the garage at about 60 f it has the start up rattle,,
occasionally i hear a sharp metallic pop when it fires and that is very concerning
tried wix, mazda filter - no diff
0-20 and 5-20 (5-20 is less noisy)
if i hold down the gas and crank for about 5 sec there is no start up noise.

it sound like VVT actuator but i'm not aware of the nc issue.
after it starts its noise free.
the dealer kept it over night but left it outside and said they heard no noisy even though i told them to leave it inside,,, it looks like i have to tell them the issue!!!

anyone seen this issue? thanks for your input.
very nice forum,,
david
https://youtu.be/pDubRVuaCUU

[kung fu jesus]

I'm going to preface this with acknowledging I know little about the NC Miatas. The noise I hear is similar to startup on engines that have hydraulic lifters that have drained. I don't know if your car has hydraulic or solid lifters. A few notable clues:

It happens when the car sits in a warmer environment, the oil is thinner and has more time to cool, drain out.

Using thicker oil helped (0/20 vs 5/20)

My '05 BMW sometimes makes a similar noise if it has sat for a while, quiets/smooths out pretty quickly. The pop you describe would be alarming for sure, but just spitballing...do the NC3s have forged internals, including pistons?

[DB4MX5]

thanks,

buckets and shims,, yes on forged.
the thing is; 2 toyota 4 cycl in the family and they are not noisy at all. my early miata's were not like this.
BTW.. the Mazda VVT actuator looks identical to Toyota
still under warranty for a few weeks, back to the dealer i reckon.
db

[MiataQuest]

I searched the internet for any known common issues and could not find any.
I understand that you are concerned about getting any potential problem fixed before the warranty expires.

Maybe you could try to define the location/source of the noise better for the dealer. You can do this by cutting a piece of 3/4" heater hose about 3 feet long. Hold one end of the hose to your ear and the other end near the engine. (Careful to keep hands clear of potential moving components!) Then have someone start the engine for you. You may need to do this several mornings to zoom into the actual location since the noise does not last long. But each time you should be able to get closer.
Once you have defined the location, then do the overnight start-up together with the dealer having the heater hose for the mechanic to use.

Myself, I do not think you have a problem as long as the noise is gone soon after start-up. It is probably just the lifters or the VVT as was stated.

However, I do not believe in using the 0W-20 or 5W-20 oil. The auto manufacturers only specify these thin oils to meet fuel economy standards, have one oil weight to cover all seasons, and cover idiot drivers that start their car cold to immediately start driving them hard.

After the car is out of warranty I would suggest running Mobil-1 10W-30 high mileage. Just drive it easy until it reaches operating temperature, then you can run the heck out of it. The Mobil-1 10W-30 flows well at low temperatures while providing higher protection under engine load. The "high mileage" version of this oil will provide the extra protection needed to reduce wear of your timing chain and VVT .

[kung fu jesus]

I might also suggest another dealer OR an independent shop that knows this model. If they can diagnose it, they may be able to do the repairs under warranty as well, some can, some can't. At least the diagnosis will be found.

I wonder, too, if it's a similar issue like the BMWs have with their version of VVT (they call it VANOS), when the actuator goes squiffy, it rattles. I'm trying to remember if our Lexus made any sounds similar when the VVT actuator went bad...

[DB4MX5]

I might also suggest another dealer OR an independent shop that knows this model. If they can diagnose it, they may be able to do the repairs under warranty as well, some can, some can't. At least the diagnosis will be found.

I wonder, too, if it's a similar issue like the BMWs have with their version of VVT (they call it VANOS), when the actuator goes squiffy, it rattles. I'm trying to remember if our Lexus made any sounds similar when the VVT actuator went bad...

my BMW 328 is very quiet

[kung fu jesus]

Wait until your VANOS needs to be serviced. ;) Like marbles in a coffee can.

[DB4MX5]

I searched the internet for any known common issues and could not find any.
I understand that you are concerned about getting any potential problem fixed before the warranty expires.

Maybe you could try to define the location/source of the noise better for the dealer. You can do this by cutting a piece of 3/4" heater hose about 3 feet long. Hold one end of the hose to your ear and the other end near the engine. (Careful to keep hands clear of potential moving components!) Then have someone start the engine for you. You may need to do this several mornings to zoom into the actual location since the noise does not last long. But each time you should be able to get closer.
Once you have defined the location, then do the overnight start-up together with the dealer having the heater hose for the mechanic to use.

Myself, I do not think you have a problem as long as the noise is gone soon after start-up. It is probably just the lifters or the VVT as was stated.

However, I do not believe in using the 0W-20 or 5W-20 oil. The auto manufacturers only specify these thin oils to meet fuel economy standards, have one oil weight to cover all seasons, and cover idiot drivers that start their car cold to immediately start driving them hard.

After the car is out of warranty I would suggest running Mobil-1 10W-30 high mileage. Just drive it easy until it reaches operating temperature, then you can run the heck out of it. The Mobil-1 10W-30 flows well at low temperatures while providing higher protection under engine load. The "high mileage" version of this oil will provide the extra protection needed to reduce wear of your timing chain and VVT .

ok on the heavier oil.. my early Miata's i put in 10-40. i tried syn (1 qt ) Lucas with the 0-20 and got no better results. got the oil sample tested and the visc and flow was just 2 points out of spec.

[DB4MX5]

I searched the internet for any known common issues and could not find any.
I understand that you are concerned about getting any potential problem fixed before the warranty expires.

Maybe you could try to define the location/source of the noise better for the dealer. You can do this by cutting a piece of 3/4" heater hose about 3 feet long. Hold one end of the hose to your ear and the other end near the engine. (Careful to keep hands clear of potential moving components!) Then have someone start the engine for you. You may need to do this several mornings to zoom into the actual location since the noise does not last long. But each time you should be able to get closer.
Once you have defined the location, then do the overnight start-up together with the dealer having the heater hose for the mechanic to use.

Myself, I do not think you have a problem as long as the noise is gone soon after start-up. It is probably just the lifters or the VVT as was stated.

However, I do not believe in using the 0W-20 or 5W-20 oil. The auto manufacturers only specify these thin oils to meet fuel economy standards, have one oil weight to cover all seasons, and cover idiot drivers that start their car cold to immediately start driving them hard.

After the car is out of warranty I would suggest running Mobil-1 10W-30 high mileage. Just drive it easy until it reaches operating temperature, then you can run the heck out of it. The Mobil-1 10W-30 flows well at low temperatures while providing higher protection under engine load. The "high mileage" version of this oil will provide the extra protection needed to reduce wear of your timing chain and VVT .

ive got 90+ psi cold start
(after market gage) using 5-20,, curious what 10- 30 will show.?

[DB4MX5]

I searched the internet for any known common issues and could not find any.
I understand that you are concerned about getting any potential problem fixed before the warranty expires.

Maybe you could try to define the location/source of the noise better for the dealer. You can do this by cutting a piece of 3/4" heater hose about 3 feet long. Hold one end of the hose to your ear and the other end near the engine. (Careful to keep hands clear of potential moving components!) Then have someone start the engine for you. You may need to do this several mornings to zoom into the actual location since the noise does not last long. But each time you should be able to get closer.
Once you have defined the location, then do the overnight start-up together with the dealer having the heater hose for the mechanic to use.

Myself, I do not think you have a problem as long as the noise is gone soon after start-up. It is probably just the lifters or the VVT as was stated.

However, I do not believe in using the 0W-20 or 5W-20 oil. The auto manufacturers only specify these thin oils to meet fuel economy standards, have one oil weight to cover all seasons, and cover idiot drivers that start their car cold to immediately start driving them hard.

After the car is out of warranty I would suggest running Mobil-1 10W-30 high mileage. Just drive it easy until it reaches operating temperature, then you can run the heck out of it. The Mobil-1 10W-30 flows well at low temperatures while providing higher protection under engine load. The "high mileage" version of this oil will provide the extra protection needed to reduce wear of your timing chain and VVT .

update; i got around the start up noise by pulling it in gear as soon as it starts, this pull the idle down to a normal idle. also, another find== im havinng spark knock at 4k rpm and goes away at 4500, checking the timing advance it was going to 50 degrees..when i changed from 10-30 to 0-30 it only goes to about 30-35 degrees.... therefore, should i conclude that the 10-30 was affecting the vvt causing the 50 degress advance.. for two weeks with the 0 30 it has shown normal advance timing. but still spark knock (another subject that i havent figured out using 93 octance)