24 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996 Coolant Leak...
Leading reported evidence
Check i will never know if
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
Until I drop the engine and check I will never know if that first manifold bolt is in right.
Leading evidence: 'Check i will never know if' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check i will never know if' (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.
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.
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
Those are the AOS hoses so it's the same as replacing the AOS.
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.
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.
24 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: 20261027T020439Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
good afternoon. I have a 2003 996. It is leaking coolant at a good rate from the front of the engine(right behind the back seat). It doesn't seem to be coming from the water pump or the filler tank. Any suggestions of what it could be?
Easy diy as shown in that thread. Just remove the two small bolts and be prepared to catch the 1.5gal of coolant gushing out when you remove that plate.
But first you should visually insect that area to confirm it's indeed that plate leaking. It could also be other places like coolant/oil heat exchanger or coolant hoses.
So it seems like the leak is coming from a 90 degree hose towards the top of the engine in the back. Any ideas? Doesn't seem like its easily accessible.
There is a coolant supply hose and return hose that go to the AOS. Besides what has already been pointed out I can't think of any other coolant hose back there on top of the engine. So staring into your engine bay, if coolant is on the right side of the engine then oil cooler or coolant plate. If it is on the left side, coolant hoses to AOS.
And correct, not easily accessible at all. Might as well do the whole AOS replacement job if that is where you need to go. A real PITA actually.
DBJoe996 - When you're looking into the engine from the back of the car. The leak is towards the top left. The coolant fill tank is also on that side. Thank you guys for the help.
Joe is right. There are only 3 coolant hoses at the "back" (top) of the engine, marked by the yellow dots. The right two are the ones connected to the AOS. All of them will be a total PITA to change out.
Those are the AOS hoses so it's the same as replacing the AOS. No need to remove the engine but you will need to lower the engine (by undoing the engine mounts) as much as you can. It's quite a painful job.
Been there done that, and it is a royal PITA job. Until I drop the engine and check I will never know if that first manifold bolt is in right. In fact, I told myself if I ever have to do that again, I will either pay someone to do it (that I trust to do the job right) or drop the engine and do every maintenance item I can think of. If you search you'll find some good write ups on AOS replacement, but standby, this one will challenge you in unbelievable ways, your mechanical abilities and patience, and your tool box.
I've heard dropping the tranny makes the AOS a much simpler job then going in through the rear. But if you go the normal route, loosen the manifold bolts before wrestling with the plenums.
OK, time for a daft question, but I will ask it anyway. I have a 997.1 2005, 137k miles with exactly the same issue, one of the small protruding arms from the top of the AOS connecting to the coolant pipe has a hairline crack and its leaking. I live in Texas and whilst it is my only daily driver its rarely cold. Why not use a connector to connect the in and out coolant pipes and bypass the whole dam AOS? Will this cause a problem for daily running?
I don't mind engine out and doing the job if I can time it with a new clutch (done a 60k) or other work, but a significant bill just for this seems like a waste.
What do you you all think?
PS: I can reach the AOS from under neither the car so although it wont be easy I think I can get to both pipes with a little struggle.
Cheers
Yes, you can connect the coolant hoses together to bypass the AOS. I would do it back by the air filter box so you don't have to contort yourself under the car. The supply hose is next to the alternator and the return line is over by the secondary air injection hose on the 3 way coolant hose coupler. Given that you are in Texas this really should not cause any problems. The AOS coolant hoses provide coolant to the AOS to help condense the oil mist when it is cold out.
