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Model specific boards => Golf mk4 => Topic started by: Mk4_AUM on 24 April 2019, 20:27
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Hi everyone
I bought my mk4 last November and bought the car with a few misfiring issues which I have sorted now, recently the car has been getting some form off backfiring from the engine bay (not exhaust all stock) now first off all before I go any further the car is completely stock other than a forge DV and a custom stage 1 remap which punches out a tidy 230bhp but this remap has been designed to have specific mods done to the car first. Which is a oversized turbo intake pipe (TIP) and a 3"de-cat downpipe along with a performance exhaust.
I haven't yet upgraded these and still am in the process of doing so, back to my original problem the backfiring seems like there is engine compression getting into the coolant system, the pops I hear from the engine bay are coming from the header tank and any pipe to do with the coolant system. Also under boost the car surges almost... cant think off any other way to explain but when it surges and you let off the throttle the bang then happens?!?!?!
I've been told by the previous owner it could be the re map because the car hasn't got the correct equipment to punch out what it can and what its capable off.
Things I've replaced new:
4 BRAND NEW BOSCH COILS
NGK BK7RE PLUGS
BRAND NEW BOSCH BANK 1 LAMBDA (2ND IS DELETED)
NEW THERMOSTAT (WAS GETTING STUCK THOUGHT WAS BACKFIRE ISSUE)
My question is would the remap be my issue here if I upgrade the tip and exhaust I shouldn't get any more backfiring from my coolant system and the surging will be gone?
Thanks for taking the time to read I hope someone can help me :undecided:
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Get the car scanned for fault codes and I can't see the map being at fault though
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Ok will do, any insight on the backfiring and what that could be?
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That sounds off... There should be nothing engine compression related anywhere near the coolant system. I hate to suggest it but I'd get the engine checked over for potential head gasket problems.
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I'd agree with Mr Orange
Surely if you want to rule out the map issue you can get someone to flash a stock map back onto it for not very much?
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Orange- I thought it was of as well never had anything like it before, there was no signs off head gasket going no overheating no gunk...
Simon- thatvis my next option if this cat doesn't work and also a sniff test.
After doing some research I think I've found a potential culprit, when I get the popping sound I then check it after and I'm getting a white powder almost like flour consistency over pipes/header tank and bonnet. From what I've read I think its catalyst which leads me to think my cat is the issue weather its blocking up under high boost I dont know...
I am tomorrow going to take it out and replace it with a 3"de cat and see if this resolves my issue will keep you all posted thanks
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Did you get anywhere with this? From your description it sounds like your coolant reservoir tank is blowing off due to excess pressure.
This is going to be from cylinder compression entering the coolant system, so most likely head gasket failure.
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Did you get anywhere with this? From your description it sounds like your coolant reservoir tank is blowing off due to excess pressure.
This is going to be from cylinder compression entering the coolant system, so most likely head gasket failure.
Head gasket failure on a 1.8t :grin: :grin:
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Head gasket failure on a 1.8t :grin: :grin:
huh?
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Head gasket failure on a 1.8t :grin: :grin:
huh?
How many head gasket failures have you seen on a 1.8t as none of my 35 of them have ever failed
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Just because you have never experienced it, doesn't mean it hasn't happened. A number of factors could cause head gasket failure, for example a failed fan controller at some point could cause the engine to overheat and a gasket fail or worse yet cause the cylinder head to crack.
From his description of hearing popping from the expansion bottle and 'white powder' on the bonnet, it indicates the coolant system is over pressurising. So I am interested to hear what you think the cause is?
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Just because you have never experienced it, doesn't mean it hasn't happened. A number of factors could cause head gasket failure, for example a failed fan controller at some point could cause the engine to overheat and a gasket fail or worse yet cause the cylinder head to crack.
From his description of hearing popping from the expansion bottle and 'white powder' on the bonnet, it indicates the coolant system is over pressurising. So I am interested to hear what you think the cause is?
I don't think I tend to find the problem :wink: but I've never seen a 1.8t head gasket fail an I've had them running close to 300bhp at crazy temperatures and never once had head gasket failure
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What would you define as crazy temperatures?
As long as the coolant system is working as designed, it is never going to over-heat, and certainly should not be experiencing 'crazy temperatures' whether it is 150bhp or 600bhp...
Basically you have nothing positive to add to this thread, you haven't experienced a head gasket failure therefore it can never happen.
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What would you define as crazy temperatures?
As long as the coolant system is working as designed, it is never going to over-heat, and certainly should not be experiencing 'crazy temperatures' whether it is 150bhp or 600bhp...
Basically you have nothing positive to add to this thread, you haven't experienced a head gasket failure therefore it can never happen.
Have you experienced a head gasket failure on any 1.8t engine
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I am still curious of what you call 'crazy coolant temperatures'?
I have, a number of times. One particular instance was that the fan controller had failed. The owner was unaware and whilst sitting in traffic the car over heated. Head gasket failed, head cracked and radiator had a hairline crack. The owner hadn't noticed that the coolant had increased out of its safe operating range.
Side note: its no wonder an alarm is not triggered when coolant over heats....
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I am still curious of what you call 'crazy coolant temperatures'?
I have, a number of times. One particular instance was that the fan controller had failed. The owner was unaware and whilst sitting in traffic the car over heated. Head gasket failed, head cracked and radiator had a hairline crack. The owner hadn't noticed that the coolant had increased out of its safe operating range.
Side note: its no wonder an alarm is not triggered when coolant over heats....
Was this in a 1.8t
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Yes, this was in a 1.8T.
But sure it could happen in any car...
Why are you so adamant that it cannot happen? And I am still curious as to what you define as 'crazy temperatures'?
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Yes, this was in a 1.8T.
But sure it could happen in any car...
Why are you so adamant that it cannot happen? And I am still curious as to what you define as 'crazy temperatures'?
I'm so adamant due to having over 35 of these and never seen one head gasket failure and crazy temperatures was having a turbo and manifold glowing every day for 4years
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So 'crazy temperatures' you are talking about are in fact exhaust temperatures, not coolant temperatures....
This back and forth is getting ridiculous, the OP is looking for some pointers on what could be causing his issue. All you have advised is that because you have not experienced any coolant over temperature issues, that it can simply not happen.
I'll stand by my original post, from the symptoms they are describing, it sounds like it is a head gasket failure. This is just my opinion, but head gasket failures can of course occur on any engine not just 1.8T's.
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So 'crazy temperatures' you are talking about are in fact exhaust temperatures, not coolant temperatures....
This back and forth is getting ridiculous, the OP is looking for some pointers on what could be causing his issue. All you have advised is that because you have not experienced any coolant over temperature issues, that it can simply not happen.
I'll stand by my original post, from the symptoms they are describing, it sounds like it is a head gasket failure. This is just my opinion, but head gasket failures can of course occur on any engine not just 1.8T's.
If you read my first post you will see I advised to have the car scanned I never pointed straight to a head gasket like you have I only pointed out it doesn't happen after you said it was that
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And I agree, first port of call should always be get the car scanned. There is a lot to gained from reading fault codes or logging sensor data.
I never said it was explicitly a head gasket failure, but from there description it does sound like one. You implied that because you have never experienced it throughout the 35 variants of 1.8T that you have owned, that it simply cannot happen. Just because you have experienced 'crazy temperatures' from the exhaust gasses and never experienced a head gasket failure because of it, has no bearing on whether or not it can happen to a modified or standard car.
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And I agree, first port of call should always be get the car scanned. There is a lot to gained from reading fault codes or logging sensor data.
I never said it was explicitly a head gasket failure, but from there description it does sound like one. You implied that because you have never experienced it throughout the 35 variants of 1.8T that you have owned, that it simply cannot happen. Just because you have experienced 'crazy temperatures' from the exhaust gasses and never experienced a head gasket failure because of it, has no bearing on whether or not it can happen to a modified or standard car.
Any part can fail I'm not that stupid but a head gasket doesn't just go there's always a reason why it's overheated in the first place that should always be checked first before even trying to diagnose a gasket failure
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You are contradicting yourself there.
You need to find the problem first before you can diagnose why it happened....
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You are contradicting yourself there.
You need to find the problem first before you can diagnose why it happened....
No I'm just not guessing what the problem is with the ops car
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You are contradicting yourself there.
You need to find the problem first before you can diagnose why it happened....
No I'm just not guessing what the problem is with the ops car
And neither am I. I am merely going on the OP's description of the problem and then my own experience. I am offering up my suggestion of what I think the problem is, nothing more. I am not asking them to jump straight in and pull the head on the car. I am suggesting they look into a potential gasket failure for the source of there problem. They need to find the problem first before they can go looking for what caused it.
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You are contradicting yourself there.
You need to find the problem first before you can diagnose why it happened....
No I'm just not guessing what the problem is with the ops car
And neither am I. I am merely going on the OP's description of the problem and then my own experience. I am offering up my suggestion of what I think the problem is, nothing more. I am not asking them to jump straight in and pull the head on the car. I am suggesting they look into a potential gasket failure for the source of there problem. They need to find the problem first before they can go looking for what caused it.
Well if you read it correctly you would have seen the post about the white dust how many coolants do you know that are white :grin:
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This is my last post about this because obviously, only your opinion matters.
You have obviously never seen coolant boil over, spill/spray outside the expansion bottle and dry up. It leaves a white powdery residue behind akin to what the OP is describing.
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This is my last post about this because obviously, only your opinion matters.
You have obviously never seen coolant boil over, spill/spray outside the expansion bottle and dry up. It leaves a white powdery residue behind akin to what the OP is describing.
My opinion was to get the car scanned by someone that knows what there doing
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*click*