Dodge Challenger Forum banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 7 of 7 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hi All,

I have a 2014 Dodge Challenger R/T (39,000 miles).

Warranty expired in June this year (pretty horrific timing but thats life).

Problem: Check engine light, P0300 and P0308 codes

Diagnosis:
Verbatum from the shop.

"Performed status compression test on cylinder number 8 (185PSI) and cylinder number 4 as a comparison (215 PSI). Performed cylinder leak down test on cylinder number 8, found leakage from intake manifold (indicating possible intake valve leakage). Cylinder number 4 has virtually no leakage. There is definitely a problem with cylinder number 8 (intake valve issue), could be a cracked valve, leaking valve seat etc. Suggest complete compression test to evaluate entire engine.

Compression test results:

1. 210 PSI
2. 215 PSI
3. 215 PSI
4. 215 PSI
5. 215 PSI
6. 215 PSI
7. 210 PSI
8. 185 PSI"
The shop is suggesting total replacement of the heads ($$$$$), what are the forum's thoughts on this? If I have 7 valves performing well why wouldn't the solution be focused on the under-performing valve instead of outright replacing everything?

Thanks in advance!
 

·
Premium Member
Joined
·
1,133 Posts
Hi All,

I have a 2014 Dodge Challenger R/T (39,000 miles).

Warranty expired in June this year (pretty horrific timing but thats life).

Problem: Check engine light, P0300 and P0308 codes

Diagnosis:
Verbatum from the shop.



The shop is suggesting total replacement of the heads ($$$$$), what are the forum's thoughts on this? If I have 7 valves performing well why wouldn't the solution be focused on the under-performing valve instead of outright replacing everything?

Thanks in advance!
You could just have a valve job done on the one head. I would honestly take it to another shop if they want you to replace both heads to fix the issues. I also think a little more trouble shooting should be performed to make sure it's actually the valve. There could be issues in the valve train that could contribute to the valve not sealing as well.
 

·
Registered
2020 Dodge Challenger Hellraisin Scat Pack
Joined
·
3,657 Posts
Hi All,

I have a 2014 Dodge Challenger R/T (39,000 miles).

Warranty expired in June this year (pretty horrific timing but thats life).

Problem: Check engine light, P0300 and P0308 codes

Diagnosis:
Verbatum from the shop.



The shop is suggesting total replacement of the heads ($$$$$), what are the forum's thoughts on this? If I have 7 valves performing well why wouldn't the solution be focused on the under-performing valve instead of outright replacing everything?

Thanks in advance!
As a non professional I am reluctant to disagree with a professional's diagnosis and recommended course of action to address a problem.

Did you ask the shop why both heads should be replaced when apparently there is just one bad valve? Why couldn't this head alone be reworked -- aka a valve job? Or if one is concerned about the possibility of one cylinder head with the refreshed valves vs. the other cylinder head with undisturbed valves having both heads treated to a a valve job?

Of course I think I understand the attraction of new heads. They are assembled at the factory and the odds are high they'll prove to be without any issues so the risk to the shop installing them is low.

And good valve jobs don't just happen. The tech performing the job has to be good and given the freedom to elect to replace what components he believes are necessary. The labor cost of a good valve job or two could probably come darn near matching what it would cost to remove the old heads and bolt on new ones.

While new heads is the most expensive solution -- at least initially -- it might prove to be the cheapest solution in the longer run.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
Roger that! I’ve booked into a local shop and I’ll ask them to dive into #8 to do some further diagnosis.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
As a non professional I am reluctant to disagree with a professional's diagnosis and recommended course of action to address a problem.

Did you ask the shop why both heads should be replaced when apparently there is just one bad valve? Why couldn't this head alone be reworked -- aka a valve job? Or if one is concerned about the possibility of one cylinder head with the refreshed valves vs. the other cylinder head with undisturbed valves having both heads treated to a a valve job?

Of course I think I understand the attraction of new heads. They are assembled at the factory and the odds are high they'll prove to be without any issues so the risk to the shop installing them is low.

And good valve jobs don't just happen. The tech performing the job has to be good and given the freedom to elect to replace what components he believes are necessary. The labor cost of a good valve job or two could probably come darn near matching what it would cost to remove the old heads and bolt on new ones.

While new heads is the most expensive solution -- at least initially -- it might prove to be the cheapest solution in the longer run.


Sorry, didn’t answer your question.

I did question the motivation for new heads both sides and your assessment above was correct. They felt that a complete overhaul would ensure a bullet proof outcome.

My hesitation is of course the cost but also that they weren’t willing to dive deeper into the #8 valve to see if it was something a little more granular.

I’ll now get a second opinion of a more focused assessment done elsewhere and consider my options from there.
 

·
Registered
2020 Dodge Challenger Hellraisin Scat Pack
Joined
·
3,657 Posts
Sorry, didn’t answer your question.

I did question the motivation for new heads both sides and your assessment above was correct. They felt that a complete overhaul would ensure a bullet proof outcome.

My hesitation is of course the cost but also that they weren’t willing to dive deeper into the #8 valve to see if it was something a little more granular.

I’ll now get a second opinion of a more focused assessment done elsewhere and consider my options from there.
The suspected/diagnosed bad valve is in the head. With the head off the valve can be checked to see if it is hanging up in the valve guide, or once removed checked to see if it is bent, has a crack, or is burned, or if the seat has been compromised in some way, or possibly the head itself has suffered a crack or developed some porosity problem.

What more assessment do you believe the shop could do?

And if the cost of the replacement heads has you stirred up do not get a quote on a full engine tear down.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
The suspected/diagnosed bad valve is in the head. With the head off the valve can be checked to see if it is hanging up in the valve guide, or once removed checked to see if it is bent, has a crack, or is burned, or if the seat has been compromised in some way, or possibly the head itself has suffered a crack or developed some porosity problem.

What more assessment do you believe the shop could do?

And if the cost of the replacement heads has you stirred up do not get a quote on a full engine tear down.

I was hoping the shop would do exactly what you described above, assess the condition of the valve, articulate that to me and then present options because there’s a good chance that headers don’t need to be replaced and a valve job might be the solution.

I’ll come back with an update.
 
1 - 7 of 7 Posts
Top