Raw Fuel from Exhaust on 2015 F-Type V6 S (Sudden Issue After Repairs)

rsensui

New member
Hello everyone,

I’m from Japan and I apologize in advance if my English is not perfect.

I own a 2015 Jaguar F-Type Coupe S (3.0L V6 Supercharged). Recently, I encountered a very strange issue: raw gasoline suddenly came out of the exhaust after about 15 minutes of idling. I’m hoping someone here has seen something similar or can offer advice. Here’s the timeline of events:
1. Initial Water Leak & Misfire:
• The check engine light first came on due to a water (coolant) leak and corrosion. Diagnostics showed random misfires, primarily in cylinder #5.
2. Repairs for Misfires:
• We replaced all the ignition coils and spark plugs. However, upon test-driving, the engine had almost no power and made a loud “bop-bop-bop” noise from the left-side exhaust. We canceled the delivery and continued investigating.
3. More Repairs (White Smoke & Sensors):
• The left bank (V6) started blowing a significant amount of white smoke from the left exhaust. We suspected sensor failures, so we replaced the crankshaft sensor and camshaft sensors.
4. Supercharger Replacement:
• The mechanic also noticed a rattling sound in the supercharger, so we replaced the supercharger with a rebuilt unit.
5. Sudden Fuel Dump from Exhaust:
• After these repairs, the engine initially ran smoothly. But when idling for about 15 minutes to warm up, the check engine light came on again, and then raw gasoline started pouring out of the exhaust. It was definitely gasoline (strong smell, not water). Fuel dripped heavily from the rear muffler area, and the mechanic immediately shut off the engine for safety.

My mechanic has 30+ years of experience (including racing engines) but has never seen fuel literally flowing out of the exhaust like this. We are trying to figure out if there is a known issue specific to F-Types or Jaguars that might cause this.

I found an older thread titled “V6-S dumping raw fuel” ( https://www.jaguarforums.com/forum/f-type-x152-72/v6-s-dumping-raw-fuel-199707/ ), but it doesn’t seem to have a conclusion. If anyone has encountered a similar situation or knows any possible causes, I would really appreciate your insights. We have invested a lot of time and money but still can’t drive the car.

Thank you very much for reading and for any help or advice you can share!

Japanese(日本語)
2015年式のジャガー F-Type クーペ S(3.0L V6 スーパーチャージャー搭載)に乗っています。最近、非常に珍しい深刻な問題に直面しました。エンジンを15分ほどアイドリングして暖気していたら、突然マフラーから生のガソリンが噴き出したのです。もし同じような症状をご存じの方、あるいは解決策をご存じの方がいらっしゃれば、ぜひアドバイスをお願いいたします。

これまでの経緯は以下の通りです:
1. 最初の水漏れ&ミスファイア
• エンジンチェックランプが最初に点灯したのは、水(クーラント)の漏れや腐食が原因でした。診断機で調べると、主に5番シリンダーでミスファイアが検出されました。
2. ミスファイア修理
• イグニッションコイルとスパークプラグをすべて交換しました。しかし、試運転時にエンジンがほとんどパワーを出せず、左側マフラーから大きな「ボッボッボッ」という音がするため、納車を中止してさらに原因を調べることになりました。
3. さらなる修理(白煙&センサー交換)
• 今度は左側マフラーから大量の白煙が出始めました。センサーの不具合を疑い、クランクシャフトセンサーとカムシャフトセンサーを交換しました。
4. スーパーチャージャー交換
• スーパーチャージャーからガタツキ音があったので、リビルト品に交換しました。
5. マフラーからガソリン噴出
• これらの修理後、エンジンは初めは快調でしたが、15分ほどアイドリングして暖気していたところで再びチェックエンジンランプが点灯し、その直後にマフラーから生ガソリンが大量に出てきました。整備士がすぐにエンジンを切りました。ガソリンの強い匂いがあったので、水や凝結とは明らかに違いました。

30年以上の整備経験を持つメカニックも「直接ガソリンがマフラーから流れ出てくるのは初めて見た」と驚いています。
F-Typeやジャガー特有の既知の問題なのか、過去の事例や原因があれば知りたいです。

過去に “V6-S dumping raw fuel” というスレッド(https://www.jaguarforums.com/forum/f-type-x152-72/v6-s-dumping-raw-fuel-199707/)を見つけたのですが、結論が出ていないようでした。同様の問題を経験された方や、原因をご存じの方がいれば教えてください。すでに多くの時間とお金をかけましたが、まだ安全に走行できる状態ではなく、非常に困っています。

何かアドバイスをいただけると大変助かります。よろしくお願いします。
 
Hi and welcome.
Misfires, engine warning light, white smoke and smell of fuel would be a failed injector based on previous posts on here.
 
Thanks a lot for your input!

Actually, the possibility of an injector failure was considered during previous repairs, but nothing showed up on the diagnostic tools at that time. All of these issues—misfires, white smoke, engine light—have happened over the past few months, so we initially ruled out injectors because there were no clear signs back then.

To be honest, we haven’t physically checked or replaced the injectors yet. So, given the ongoing problems, it’s definitely something we’ll prioritize now.

It’s been frustrating because every time we think the issue is fixed, something else pops up. At this point, we’re also considering fuel pump problems, but I agree that the injector is looking like the most likely cause right now.

Still, it’s a bit unusual that such severe symptoms have persisted for so long. Even my mechanic, who has 30+ years of experience, finds it strange.

I really appreciate your advice, and if you or anyone else have more insights, I’d be happy to hear them. I’ll keep the thread updated as we make progress.

Thanks again for the support!
 
I’d be looking at injector failure too, and it sounds like you’ve suffered from bore wash; cylinder liners and/or piston rings are worn allowing more fuel to bypass combustion and straight into the exhaust. It may have started as a slight injector weep (which won’t always produce a diagnostic code), washing the bores over time and causing other symptoms
 
Thank you again for the detailed advice!

We actually ran a compression test about a month ago, and at that time, everything seemed normal. However, considering the recent issues with fuel loss and the raw fuel coming out of the exhaust, it’s possible that the engine has suffered damage since then.

I’ll definitely have my mechanic redo the compression test to check if anything has changed. If we see signs of damage to the cylinder liners or piston rings, it would confirm that bore wash has caused serious wear.

The part that surprises me the most is how quickly this issue seems to have escalated. I’ve had the car in and out of the workshop several times over the past few months, and every time we think the problem is resolved, something new pops up. It’s frustrating, but I really appreciate the advice from this community.

I’ll post updates once we get the results from the next compression test or if we find anything else during the investigation.

Thank you again for your support!
 
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