Mayo in oil filler cap - definitelty HGF?
Discussion
Brother in law has found white, creamy gunk inside the oil filler cap of his 2004 Ibiza 1.4TDi. My first answer was head gasket failure, but he's balking at the possible costs of repair.
Could it be anything other than HGF?
If it is, how big a job is it to replace?
I know the head sometimes needs skimming - is this an occasional or often job?
TIA for replies
Edit: Just noticed the typo in the title - if a passing mod would be so kind...
Could it be anything other than HGF?
If it is, how big a job is it to replace?
I know the head sometimes needs skimming - is this an occasional or often job?
TIA for replies
Edit: Just noticed the typo in the title - if a passing mod would be so kind...
Edited by parapaul on Sunday 6th March 09:57
Short journeys coupled with cold weather can cause condensation to form in the top end which then manifests as mayo on the filler cap.
Best thing to do is find a decent indy garage and ask them to do a "sniffer test" as this will definitively tell you if their are combustion gases in the water system which is a red flag for headgasket failure.
Best thing to do is find a decent indy garage and ask them to do a "sniffer test" as this will definitively tell you if their are combustion gases in the water system which is a red flag for headgasket failure.
Had this recently in my Corsa that only gets to do short trips, looked really bad. By that I mean it was nearly an inch thick on the underside of the cap. At the time of checking I was due to pick a mate up from Stanstead. Feck it says I, got me AA card so off I set.
Cue 300 miles of perfect performance and I'm back home, white gunk completely gone.
Cue 300 miles of perfect performance and I'm back home, white gunk completely gone.
will pass this on and see how he fares. Another cause can be breather systems having a leak or blockage i believe. I dont think this tends to produce major levels of mayo though.
On the short journeys front my brothers old mk3 Astra was driven 2 miles each way to work and definitely started to look like the HG was failing. My Dad then made him do a weekly drive of 60 miles to get it nice and warm and it seemed to go away.
On the short journeys front my brothers old mk3 Astra was driven 2 miles each way to work and definitely started to look like the HG was failing. My Dad then made him do a weekly drive of 60 miles to get it nice and warm and it seemed to go away.
parapaul said:
Right, it turns out his journey to work is only 8 miles each way, and coolant looks fine. He's going to try taking the car out and letting it actually get up to temperature
He bought the wrong car, 8 miles won't get the heater going in winter, never mind getting the engine up to temp. HellDiver said:
parapaul said:
Right, it turns out his journey to work is only 8 miles each way, and coolant looks fine. He's going to try taking the car out and letting it actually get up to temperature
He bought the wrong car, 8 miles won't get the heater going in winter, never mind getting the engine up to temp. 
I've had this on a few new cars I've purchased in the past. The bottom line is I don't use my personal car enough to get the engine temps up during the week, therefore it's a natural accumulation. Must admit I was quite worried when I found it, but surely two brand new cars from the factory would show the same response if it was a fault.
parapaul said:
HellDiver said:
parapaul said:
Right, it turns out his journey to work is only 8 miles each way, and coolant looks fine. He's going to try taking the car out and letting it actually get up to temperature
He bought the wrong car, 8 miles won't get the heater going in winter, never mind getting the engine up to temp. Generally, mayo in the oil cap is condensation. It's when there's oil in the water, that's the big worry.
Oil systems run on average about 4 bar, water systems run about 1 bar, some are now 2 bar on newer cars. So, it means if there's a place where oil and water can mix, oil will pretty much always go into the water, but water won't go in the oil, due to the pressure differences.
So oil in the water can mean HGF, or if your car's got a water cooled oil cooler, your oil coolers shot.
Oil systems run on average about 4 bar, water systems run about 1 bar, some are now 2 bar on newer cars. So, it means if there's a place where oil and water can mix, oil will pretty much always go into the water, but water won't go in the oil, due to the pressure differences.
So oil in the water can mean HGF, or if your car's got a water cooled oil cooler, your oil coolers shot.
sparks_E39 said:
Isn't it something like 18-20k a year for it to pay off?
I would say this is not the case now with petrol having gone up 35% in less than two years and more economical diesel now available in the used market. Having said that, some diesels don't like short journeys very much, especially ones with DPF etc.....and they still sound like tractors.sparks_E39 said:
parapaul said:
HellDiver said:
parapaul said:
Right, it turns out his journey to work is only 8 miles each way, and coolant looks fine. He's going to try taking the car out and letting it actually get up to temperature
He bought the wrong car, 8 miles won't get the heater going in winter, never mind getting the engine up to temp. Gassing Station | General Gassing | Top of Page | What's New | My Stuff