fullymatted.
Back to search
Rennlist

Blowing Hot then Cold

Add to repair workspace
Open repair workspace
Original source
6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHBlowing Hot then Cold

Leading reported evidence

Check few things

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I'd check a few things.

Original post Read captured discussion
Blowing Hot then Cold
Read full discussion summary

Leading evidence: 'Check few things' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check few things' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 6 captured posts examined · 0 partial discussions

Compare 3 other evidence results

Check hvac flaps

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Second I'd check the HVAC flaps.

Original post Read captured discussion
Blowing Hot then Cold

Replace temp

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

If i change the temp setting again same behaviour.

Original post Read captured discussion
Blowing Hot then Cold

Set warm temp

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

If i set a warm temp on the heater controls it blows out hot air for a few minutes and then blows out tepid air.

Original post Read captured discussion
Blowing Hot then Cold
Frequently discussed actions (4)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check few things

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I'd check a few things.

Original post Read captured discussion
Blowing Hot then Cold

Check hvac flaps

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Second I'd check the HVAC flaps.

Original post Read captured discussion
Blowing Hot then Cold

Replace temp

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

If i change the temp setting again same behaviour.

Original post Read captured discussion
Blowing Hot then Cold

Set warm temp

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

If i set a warm temp on the heater controls it blows out hot air for a few minutes and then blows out tepid air.

Original post Read captured discussion
Blowing Hot then Cold
Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • Rennlist: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T172408Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Got a weird heater issue which i cant see mentioned elsewhere - apologies if it has and I simply missed it. Standard 996.2 C2. If i set a warm temp on the heater controls it blows out hot air for a few minutes and then blows out tepid air. If i change the temp setting again same behaviour. Has anyone seen this or got an idea where i should start investigating? Thanks alot Martin

POST 2Original post

I'd check a few things. First thing I'd check is to make sure the carpet is dry under the dash- a leaking heater core will cause all sorts of issues. Second I'd check the HVAC flaps. This can be done a few ways, check out youtube for videos on "996 HVAC blower flap fix." There are two ways to do this, taking out the center stack and cutting open the center vent, removing the heater core (IMO the easier way), or lastly removing the dash and entire assembly (not as fun but sometimes necessary). Best of luck! --Aaron

POST 3Original post

There's a gigantic thread on here about the heater flaps. https://rennlist.com/forums/996-foru...ntn-issue.html

POST 4 / ORIGINAL POSTEROriginal post

thanks both - i'l give that a whirl over the weekend

POST 5Original post

If you turn the temp setting up to high (not a number) does it do the same thing or is it constant hot? Also is does it vary with engine speed?

POST 6Original post

First thing I would check, of course, is the coolant level in the expansion tank. It is also possible you have an air bubble in the coolant system.

This is a source reference. Confirm exact model applicability in the original material.