Executive350

After I got a check engine light I checked the codes, got P0025 and P0128 then, I took it to the dealer for a diagnosis and I was told I will have to replace the front cam solenoid (faulty sensor) and thermostat housing (stuck open) of course after I read the cost (around 3000$ that's with taxes and including the diagnoses 300$). I decided to replace them myself or try to find a good mechanic since the parts wouldn't cost more than 500$. But the problem is I am not sure how to find OEM parts to buy since i don't know what are the OEM brands are so thought I could get the help I need here. Thanks.

CaliBenzDriver

Can you translate your fault codes into English?
I am confused as to what's happening because solenoids are not sensors.

Can you provide us with background information about the issue you're having?

Plutoe

on your service bill there are listings of parts need to be replaced----those are the parts you can google to locate sources-----if you dont understand this process better to let a mechanic do the complete job------as loads of labor associated with this job
FYI----P0025 is left exhaust camshaft positioner sensor--faulty
P0128 is accelerator position sensor(B37) faulty #2 hall sensor

Executive350

I am already aware of the meanings of the code but didn't write it out since I already know what is exactly the problem source all I wanted to understand is where to get OEM parts but I will just buy them from the service directly or online mb parts. And actually P0128 Is "Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) that's what I got in the scanner. And since I still didn't get the service bill itself didn't know what the parts where exactly they wrote me in message that the thermostat is stuck open only and the front cam solenoid (fault present).

Executive350

Well the name "Solenoids" is what they sent me in the message from the dealer which surprised me I thought they will email me or call me but whatever I googled around and I assume that the 2 things I will replace are in the pics I will post. For the codes P0128 Is "Coolant Temperature Below Thermostat Regulating Temperature"

And the P0025 is "Exhaust (B) Camshaft Position Timing Over-Retarded (Bank 2)"

About issues I'm not having issues really the car drives okay drove it 1.5 day and got the check engine checked I had the P0025 in stored and P0128 in pending after a week (I didnt drive it much till now) the P0128 was moved to stored so i assume that the computer confirmed the problem? The car doesn't get above 80 much doesn't hit 90 even on highway or when driving in the city takes time to get up to 40 while idling and it feels a bit underpowered? I'm not sure since I havent driven many cars before so yeah that is all the problems I got. Here are the pics of parts I assume I need



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robbieas

Those cam solenoids are pretty easy to replace, I've done all 4 of mine. You can get OEM part from Amazon.

I didn't use a repair guide, they are right on the front on the engine, it's pretty easy to see it's just removing 3 screws and unplugging the cable. There really isn't much to it.

I also did the thermostat.... I don't have a link to a guide I used, but that's a pretty basic repair and there are definitely walkthroughs available. And you shouldn't have much trouble finding the part... FCP Euro is awesome though, start there if you have any trouble finding things.

Executive350

So i found this website called MB parts but i'm not sure if it's a legit site (looks legit)
https://www.mbparts.ca/

CaliBenzDriver

Great description

I have good news about your stored code for bank2 camshaft position.
It is the chain tensioner , not the solenoids.

To be sure... simply switch two of them from bank1 to bank2. I bet the code wont change at all.

As for thermostat... replace new fluid and tstat

Executive350

Hi thanks for the explanation but in the diagnoses it said for the thermostat it needs replacement since it's stuck open and there is a leak in the camshaft solenoids. soo i'm not sure if it is the chain tensioner?

Executive350

For the thermostat something happened so basically when i got the check engine light I checked it with the scanner and it showed me the P0025 and P0128 in the beginning the P0025 was in stored and the P0128 was in pending for some reason I assumed that the stored is the unimportant one and the P0128 is causing the check engine so I ignored it... but then when i googled the meanings I understood which is which. after the check engine came on and the scanning for the codes I changed the oil and topped the coolant in a Take5 service place in BC which I later regretted since weird things happened could be completely unrelated to the codes really but I just wanna explain what happened with me...


so i ask the guy what kind of oil are you gonna put he said 5W40 i said great and told him if he can top off the coolant i wanted to replace but went with topping it off instead then when he came with the oil i expected an actually 5W40 bottle with the name and everything on it but to my surprise he brought out some big jug with oil in it was unclear what kind of oil he put which is making me nervous about driving it now (i will change it immediately after the repair). Then lastly he topped off the coolant which was a blue color (same as the one in the car) that same day after I arrived home i checked with the scanner the P0025 was in it's place in stored BUT the P0128 moved from pending to stored.... So I'm assuming the coolant they put messed it up more than it is? I'm not quite sure all of this happened literally in front of me they didn't try to hide it something tbf but idk just seems weird.. sorry for the unnecessary information lol

I already ordered the thermostat and solenoid from mb parts i will just replace it myself I don't trust any service place anymore after the moment i saw the guy come out with a jug

CaliBenzDriver

I see... it's very wise around here not to trust anyone when the hood goes up, your wallet is open.

I want to hope you have a good local MB specialist that can help you with services.


The issue are where did the coolant go...leak: S-M-L?
Its not mystery the missing oil got burned by the engine cylinders.

Save some time to troubleshoot your VVT Solenoid issue if the new unit does not solve code. I think the tensioner will.

🤞

Executive350

Well yeah I changed only one camshaft adjuster the driver side bottom one which is Bank B as far as I can see on the pictures on the forums and i erased the codes I will drive it around tomorrow and see what happens hopefully no more check engine.... and about the coolant it's all good it is not leaking or anything it is just the adjusters leaking according to the dealer diagnosis...

CaliBenzDriver

All right, I reread your thread and see that you have a "leaking solenoid"... check others when replacing to prevent "oil in the harness" $10k repair.

Fixing many things at the same time is the great leverage DIY'ers have. The idea is to have everything complete at once and not revisit same issues multiple times if you can avoid.

Executive350

Absolutely right I will check the other three, if needed I will replace them quickly since they are really easy to work on.. Thanks for the advice.

JNLeChevet

Your Dealer must have a tax payment due - rediculous estimate! The thermostat is any easy level one DIY and a good OE Wahler can be had from FCP for under $100. Would suspect the faulty solenoid diagnosis - could be hydraulic actuator, timing chain, tensioner, loose magent, slipped index wheel, bad connector, etc. Best to swap the solenoids and see if the fault code follows the solenoid. If you don't have an appropriate scaner, best to find a good Indy. Replacing the solenoid is a 1/2 hour DIY job and under $100 in parts. There must be a bunch more work in your estimate?

Executive350

There wasn't anything really it was written as 500$ for each parts plus it was written in this form 500$,3Hours labour(500$) something like this anyway I changed the thermostat and 1 solenoid which is the bank B I hope and now I will just see if the check engine pops up again idk how long it takes for it to recognize something in the engine....

JNLeChevet

A stuck open (common problem) thermostat will give the fault "engine slow to come to temperature" and throw a code and CEL. The only effect will be a cooler than normal engine resulting in slightly lower power, loss of full cabin heating and possible fouling issues if run for long time (months). Engine may eventually come up to temperature and the cooling fan will then control the temperature. No damage done. When a code is moved to "stored" it only means that the code was seen on a perevious engine cycle - not that it has been erased. "current" means that the code was set during the current engine cycle. A stored code can remain in the memory until the battery is disconnected, but the CEL will go out if it is not "current" for several engine cycles. Only the wizzes that made the ECU program can give you the exact answewr, but this is from dealing with Mercedes codes for many years.

Executive350

Alright so on my scanner Ancel-AD310 has 2 folders "Stored" and "Pending" as you read it already the P0025 was in stored first time and P0128 In pending (first time I checked) but then P0128 moved to "Stored" I assumed that pending is the "Current" and stored is not a problem but after googling i found out that "Stored" means there is an actual fault but looks like what you're saying is the opposite of that... anyway I changed the thermostat and 1 Camshaft solenoid magnet and I drove 2 days everything is going good car feels more powerful now since it's warming up quicker... Thanks.