Head Gasket Failure - N52B30. Advice please

[JonLeeper]

Good afternoon all,

It's been a long time, but I'm back for a question and some advice, please.

My e86 coolant expansion tank blew up a couple of weeks ago. I replaced that and then one of the hoses kept coming off at random intervals. I've just had a garage run a test and the head gasket has gone and gases are getting into the coolant. This means it's highly likely that at some point the coolant system is being pressurised by the head gasket leak, hence the blown hose. Otherwise, the engine runs OK, @130,000 miles.

So is this likely to be terminal? I've never had to take the head off a BMW, let alone a high mileage one. My mechanic has heard stories of head stud problems and doesn't have any of the timing kit to do the job anyway. So I don't know if it's worth investigating further or just looking into a new engine.

Thoughts?

 

[j3nks79]

A second hand N52 is circa £3k
If you paying someone to do your headgasket you’ll be looks around £1200ish.
You won’t know if the head is damaged until you take it off. Then it will need pressure testing and a skim.

 

[JonLeeper]

A second hand N52 is circa £3k
If you paying someone to do your headgasket you’ll be looks around £1200ish.
You won’t know if the head is damaged until you take it off. Then it will need pressure testing and a skim.

That's quite a bit cheaper than I was thinking. I was expecting twice that, and then anything else on top. Is that a figure you have faith in?

 

[j3nks79]

A second hand N52 is circa £3k
If you paying someone to do your headgasket you’ll be looks around £1200ish.
You won’t know if the head is damaged until you take it off. Then it will need pressure testing and a skim.

That's quite a bit cheaper than I was thinking. I was expecting twice that, and then anything else on top. Is that a figure you have faith in?

The second hand engine I guess you can add fitting labour costs. Rocker cover gasket and other consumables

And the £1200ish all in would be the total for the headgasket job.
But you may take the head off and it could be cracked. But you won’t know until it’s removed and tested.

 

[Rockhopper]

Plenty on Ebay for under £2k. That'll get you one taken straight out of a scrapped car and put on a pallet.

 

[Mike6]

I have done a few head gaskets in my time but thankfully old cars and not a zed .
I have only ever changed a head gasket because there were visible signs around the outside where the head meets the block or where water was getting into the oil making a right old mess.
I wonder what test he carried out. If gases and oil were getting into the coolant I would expect to see some signs of it. Could it be a failing thermostat or water pump over pressuring the system.
Others more knowledgeable than me might be able to offer other suggestions but I do know head gasket problems are not common on these engines

 

[j3nks79]

I have done a few head gaskets in my time but thankfully old cars and not a zed .
I have only ever changed a head gasket because there were visible signs around the outside where the head meets the block or where water was getting into the oil making a right old mess.
I wonder what test he carried out. If gases and oil were getting into the coolant I would expect to see some signs of it. Could it be a failing thermostat or water pump over pressuring the system.
Others more knowledgeable than me might be able to offer other suggestions but I do know head gasket problems are not common on these engines

You use a block tester (sniff tester). You put a chemical in a tube (blue colour). Then put it on to the expansion bottle. This then changes colour if exhaust gases are going into coolant system.

 

[Rockhopper]

If the water pump fails or there are other cooling issues and its not spotted soon enough then head gasket failure will follow soon after.

 

[Mike6]

I would still get a second opinion before tearing everything apart

 

[Ed Doe]

Welcome to the 2024 - where the first recommendation is to bin the engine rather than replace the head gasket :lol:

Come on guys - Head gaskets aren't that complicated, if your mechanic is saying he's worried about doing it he's the wrong man for the job. Take it to a BMW specialist, they'll sort you out no problems.

Just be aware that a lot of the fixings for the N52 are single use, so make sure whoever is doing it works on those engines regularly and knows what they can and cannot reuse. I highly recommend TWG in Camberley - bit of a trek potentially but I'd suggest entirely worth it to be in the right hands for the job. Alternatively Ross @ RBM is also very good.

Let's also be clear, there's absolutely ZERO guarantee that a replacement 2nd hand engine isn't also hiding issuses, which will only present themselves once all the money is spent putting the engine in the car... Seems a very silly way to spend a lot of money vs just replacing the head gasket on your existing known engine.

 

[j3nks79]

Nobody has recommended he changes the engine?

 

[Ed Doe]

Nobody has recommended he changes the engine?

your first two posts read as if you're suggesting replacing the engine rather than do the head gasket...

 

[j3nks79]

Nobody has recommended he changes the engine?

your first two posts read as if you're suggesting replacing the engine rather than do the head gasket...

No it doesn’t. It was clearly giving the op the costs involved. No recommendations were mentioned.
I find it funny people who give advice about doing a an easy headgasket wouldn’t have a clue how to do the job themselves.
Another forum expert giving out advice when they don’t know one end of a spanner from the other.

 

[Ed Doe]

Nobody has recommended he changes the engine?

your first two posts read as if you're suggesting replacing the engine rather than do the head gasket...

No it doesn’t. It was clearly giving the op the costs involved. No recommendations were mentioned.
I find it funny people who give advice about doing a an easy headgasket wouldn’t have a clue how to do the job themselves.
Another forum expert giving out advice when they don’t know one end of a spanner from the other.

1. Yes it does - '£3k for a new engine, or £1200 for a headgasket but you wont know if the head is cracked and therefore scrap until you take the head off' reads like 'do the engine because you'd be £1200 down with a fucked engine otherwise'. Perhaps add 'You also don't know what you're getting for a £3k engine on a pallet, whereas depending on how long you've run the engine with a blown HG you'll probably be fine with skimming the head and putting it back together' and it sounds less like 'yeah don't get the HG done it could be fucked anyway'.
Anyway, as I say that's how it reads, but since you're jumping down my throat with your big boy internet shoes please explain to me how you've diagnosed a high % chance of a cracked head from the OP's original post. I'd suggest that likelihood is so low as to be inconsequential, unless the OP has driven it for miles and miles with the headgasket blown, which we don't know but can probably say is fairly unlikely.
2. Back at you - where did I imply HG was easy or that I could/would do it myself - and what relevance is my ability to do a head gasket myself anyway for that matter?
3. If someone is asking for advice over whether to get a head gasket done - surely the right advice is 'take it to someone who knows the engines and can do it for you'? With the correct tools and knowledge it should not be a difficult job - it should be bread and butter for a proper garage - go on ask me how I know :roll:
4. Finally where is your factual basis for arriving at the conclusion I don't know one end of the spanner from the other? Critically I'm even more interested to understand whether my experience with doing head gaskets myself has a bearing upon my ability to make sound recommendations to find a reputable specialist mechanic to undertake the work?

And if you're interested in my CV of relevant experience in providing advice on an issue, here are some pics of when I had my head removed and skimmed on my M. As you're such a forum expert, you'll note the Redish Motorsport watermark, because, you know, I don't know which end of the spanner to hold, so I found a reputable specialist to do it for me. Much in line with my advice above. :wink:

 

[j3nks79]

You need to learn how to read a statement properly.
This is what was said.

“ A second hand N52 is circa £3k
If you paying someone to do your headgasket you’ll be looks around £1200ish.
You won’t know if the head is damaged until you take it off. Then it will need pressure testing and a skim”

No recommendations or mention of “cracked head”.
Just explaining costs to the op.

You made yourself look like a tit with your opening paragraph.
“ Welcome to the 2024 - where the first recommendation is to bin the engine rather than replace the head gasket”

 

[Mike6]

Oh dear, comments can often be misconstrued and people take offence. But coming back to the original query, I would at least get a garage to take the head of for a proper diagnosis. From my experience of removing cylinder heads, but not on a zed, I would guess around 3 hours work for someone with proper tools.
You will then know what territory you are into, but most likely it's just a failed gasket.

 

[Ed Doe]

But you may take the head off and it could be cracked. But you won’t know until it’s removed and tested.

No you're definitely right, I must have misread, you never said 'cracked'

Anyway jolly interesting as this is, it's not really helpful advice for the OP. Which, to just repeat for completeness would be 'take it to a bmw specialist who will be able to do the head gasket with relative ease.'

Or at least as above, take it to someone who knows what they're doing to take the head off and take a look.

 

[j3nks79]

But you may take the head off and it could be cracked. But you won’t know until it’s removed and tested.

No you're definitely right, I must have misread, you never said 'cracked'

Anyway jolly interesting as this is, it's not really helpful advice for the OP. Which, to just repeat for completeness would be 'take it to a bmw specialist who will be able to do the head gasket with relative ease.'

Or at least as above, take it to someone who knows what they're doing to take the head off and take a look.

Again it says you “may” take the head off and it “could” be cracked.

You are misreading everything. Slow down a bit and read what it says. It’s how you have read and interpreted it and not what was actually said.
You jumped all over a statement that you interpreted wrong from the start.

 

[bigwinn]

OP

Before you chuck it all in and spend a packet- invest in some steel seal. It MAY resolve the issue. I know a few people who endorse it working well and you have nowt to lose

Some will have negative views on the product sure (I’m now running for cover) and it’s your decision to use it- only you know your longer term plans for the car etc

Good luck

Stuart