HELP. Desperation, last resort before scrapping Project 16v.

[Piggy]

Ok. 
So essentially I am a hairs breadth away from scrapping the lemon and selling it's bits.

The overheating is still an issue.

Replaced on the car the following;

4 pistons
The head
Headgasket X3
Thermostat X 3
Water pump X2
Coolant x10274829202
Radiator
Injectors (refurbed)
R70/for (refurbed/new)


The gauge and sensor tests out fine. 


The problem;


Driving normally it's ok, does get up to temp about twice as fast as I would expect. 

Lean on it and it gets up to opening stat temp fast. 

Keep leaning on it, like persistent hard pulls in multiple gears and the temp keeps rising.... Till I dare. 

As soon as you back off, temps drop back again. 



I am open to any and all ideas... End of April there will either be a "fixed" thread for the lemon... Or a breaking one.

I just can't cope. I'm losing sleep, spending a fortune of time and money and generally feeling in a very dark lonely place because of it. 

I appeal to all brains. Help. :-(

[Magenta Sunset]

going from your list, i'm guessing you had the whole block apart?
my limited experience would have suggested some sort of blockage in a waterway.
would endoscoping it be an idea?

[wainwrightj]

I'm not going to pretend I have a clue what I'm talking about but my wrong ideas might get others thinking

Could it be the piston ring gaps being too big or small creating too much friction? If this was even a possibility it might explain why the temps go up as you give it some?

Could it be an in-balance of intake vs exhaust? Would a restrictive exhaust/ exhaust manifold be holding the hotter exhaust gasses in the head or something? This again if possible would explain the correlation with footing it.

Short of that could it be something simple like a blocked coolant hose that's only allowing enough coolant through when the engines not under alot of load?

Maybe try a thermostat that opens sooner?

Maybe a bigger radiator fan?

I'm honestly not sure as you can probably tell

[Magenta Sunset]

where did you source the head from? has it been crack/flow/coolant gallery checked?

[Mighty306]

Like Wainwright, I'm far from an expert on diesels, but based on everything you've said you've checked, I'm going to throw out a some more ideas:

Injection timing
Valve timing
Compression (I'm guessing it's not this as you said you ran it without boost & still had the problem.  Do you know what the compression gets to?)

I don't know to what extent you built the engine based on tried & tested combinations of components or whether you've experimented a bit?  Rather than scrap it would you not consider some input from a professional engine builder?  I know it's going to cost you yet more money and the idea would have been to complete this project on your own but ........surely, giving up is not an option.  It's not admitting defeat to get someone else to look at it.

What has the process been to map it btw?

---

Just another thought!  Have you tried running it without a thermostat in the cooling system?  Also, I am I right in thinking you upgraded the water pump?  Any chance one of the coolant hoses is collapsing at higher RPM?

[gti6man]

I know nothing either... but does the engine have an oil spray bar to lubricate the camshaft could be blocked....?

[JTaylor2005]

Is there any way the water pump could be running at a faster rate than normal? Strange belt routing or a smaller pulley for space etc?
Spinning a water pump too fast causes cavitation and ruins the flow rate.

Does it have an oil to water cooler or is it an external oil cooler?

[Uberderv]

As the engine is from another car have you correctly connected the water system up?

Who has done the mapping? From what I've read incorrect timing will put more heat into the head, more IQ = more advance.

[Piggy]

Mapping is pro. Best I know.

No oil spray bar.

Water pump is correct and not any different piping to OEM.

Radiator is huge... Can cool a 500bhp nissan.

Head has been proffesionally skimmed and tested.

Thermostat is working correctly

System does not work with stat removed due to bypass

Hedging bets at something blocked or not flowing correctly. Possibly timing... If a cam has slipped.

Will be attempting to test those two things this week

---

That's for all ideas

---

...stock oil cooler/heat exchanger.

[306Dan]

Does the coolant system take on air after its got hot? Any chance of a cracked block?

Sorry I don't know the xud11's so more a guess off other derv's ive worked one

[Magenta Sunset]

you may be on the right path suspecting a blockage.

---

ps
https://www.ebay.co.uk/i/172983749047?ch...632&crdt=0

[Piggy]

Does the coolant system take on air after its got hot? Any chance of a cracked block?

Sorry I don't know the xud11's so more a guess off other derv's ive worked one

This is the lemon. Racetractor is dead and gone.

---

you may be on the right path suspecting a blockage.

---

ps
https://www.ebay.co.uk/i/172983749047?ch...632&crdt=0

Got one .not sure it could help

---

No air or pressurising

[Mighty306]

More shooting in the dark Piggy ....is it possible the OEM pump struggles to get coolant through the performance rad once you wind the car up? Just read something about some of them needing to run higher coolant pressures to work properly.

I guess you fitted an upgraded rad because you thought the engine was going to produce more heat than a standard rad could handle?

[Magenta Sunset]

more thoughts whilst trying to sleep.
please bear with me on this.
what's the history of the lump? is the original or sourced elsewhere?
has it been flushed/descaled?
if it's not mechanical, could it be electrical? ie, engine/dash earths? my gauge pod is powered with a cigarette plug. if I jiggle the plug, the readings change.
do the sender and gauge match? ie a 0-50 psi gauge would need a 0-50 psi sender. the sender itself is just a variable resistor.
is the sender one or two wire? 1-wire feeds to earth, 2-wire feeds "through".
finally,
consider getting a meat thermometer (a skewer with a gauge attached) and some self-amalgamating tape, stab it carefully into the top hose when the car is up to temp, and read the coolant temp directly. the tape is to seal the hole afterwards, (you need to stretch it slightly to self stick).
Oh, and are you using waterless coolant? I gather it doesn't suit all cars.

[Mighty306]

Apologies about my earlier suggestion of running it without a stat btw. I'll happily admit I didn't know about bypasses n also didn't realise it was a pretty bad idea to run a modern engine without a stat installed.

I perhaps shouldn't be getting involved when I have such big gaps in my knowledge!!!!

[Midnightclub]

What are your oil temps looking like compared to water?

[Piggy]

Oil temps at 90... I've seen 110 when I was really really ragging it.
The gauge and sensor all check out.
Already used other sensors to test. Continuing to do so.

The block is the questionable bit. Got it from Micky from a 206 he scrapped. But it was gutted and cleaned when I built it up.

Oem pump be fine with this rad. This rad turned out cheaper than a Valeo or nissens, hence the choice.

[JTaylor2005]

Sounds like there can't really be much else :S is there anything stupid like the gaskey having a blank section in it as its a hybrid head/block system?

[Magenta Sunset]

Oil temps at 90... I've seen 110 when I was really really ragging it.
The gauge and sensor all check out.
Already used other sensors to test. Continuing to do so.

The block is the questionable bit. Got it from Micky from a 206 he scrapped. But it was gutted and cleaned when I built it up.

Oem pump be fine with this rad. This rad turned out cheaper than a Valeo or nissens, hence the choice.

I've had similar oil temps, esp when queuing past Thiefrow.

[Ben_w]

Ignore me.......

[Magenta Sunset]

Ignore me.......

huh?!

[Piggy]

Sounds like there can't really be much else :S is there anything stupid like the gaskey having a blank section in it as its a hybrid head/block system?

Checked that too.

[306Dan]

Have you had a pressure tester on it at all?

[bashbarnard]

Running retarded timing makes them very hot. Maybe try advance the crank a little in regard to the cams. Obviously this isn't a factory engine. Took me a while and a few attempts to get the timing working on the 2.1 8v Indo e a while.back.

[Dave]

Go back to basics, try get a basic flow measurement through the rad. Get a second measurement on the temps too.
If there is no flow through the rad then work backwards.
Remove stat and force flow through rad. If there is no pressure then its a pump issue. If there is flow going through block and through the rad as OEM specs, then your engine must be putting out the heat, or your rad inst radiating heat (airflow clear?) - at the moment the details from the thread are hazy to whats defo been tested/hasnt.

If you know for sure the rad is transferring all this heat and still its overheating, check a correlation with your inlet/exhaust temps and EMP. When does it seem to overheat, what kind of driving, consistent? or hammering? how long to cool down, how long to heat up, need more details on how/when it occurs really if it is the block kicking out all this heat.

There is a crew on this forum who are definitely eager to help you sort this issue out.

[Piggy]

Going out early in the morning for some runs with the queries in mind.

[Piggy]

So here is some test results...

Went out this morning. Ambient temp 8/9degrees.

T= coolant temperature on housing 
M= coolant temp preMatrix
BH= coolant temp at bottom rad hose
TH= coolant temp at top rad hose

After 4:30 steady driving:

T72. M69. BH60.7 TH20

7:15
T83 M83 BH70 TH77

10min. Partial load 0-60 (junction onto national)
T83 M83 BH24 TH81 (stat opened!!!)

30seconds later;
T80 M78 BH73 TH73

This is how it is general driving. It's fine (ish). 
You do a pull of average length or accelerate as you would daily... It's fine. I think the stat has to work harder than it should and it creates more heat than I would expect..but it manages it. 

18min
I then did some hard pulls... Repeatedly, braking, 3rd/4th... Braking, 4th pull, etc. 

T88 M84.5 BH66 TH81 (''heat soak''?? Rad not able to bring temps down, temps continue to rise slowly)

T88 M85 BH70 TH83 (Oil at 110)

I pull in after a stretch of 60mph at these temps. 

Stationary 19min into journey;

T87 M86 BH80.6 TH84.8

30sec later;
T89 M87 BH82.6 TH 85.5

30sec;
T90 M87.5 BH83.7 TH86.2

30sec; 
T90 M88 BH84.5 TH86.6

30sec I put fans on;
T90 M87.6 BH74 TH83.5

Fan on 1min...
T84 M80 BH64 TH78

Fan off a minute later with temps at;
T81 M78.5 BH67 TH77

Cruise off at 60mph home..
T80 M78 BH69 TH71

Gentle 0-60 (junction onto A road)
T85 M83 BH50 TH80.  (Stat has to open, rad cools it)

30min journey ends at home. Stationary. 

T81 M80 BH53 TH77.7  (oil at 90)

[Magenta Sunset]

all appear within 'normal' range.
what did you measure with?

were I able to remember where you lived, i'd try to call after work for a back to back with my car. (stock HDi)

[JTaylor2005]

30seconds later;
T80 M78 BH73 TH73

When cruising normally there isn't much of a temp change from top to bottom of the rad?


As for all the temps 90 being the peak doesn't seem too bad??

[FuST]

30seconds later;
T80 M78 BH73 TH73

When cruising normally there isn't much of a temp change from top to bottom of the rad?

IIRC the (stock)thermostat on the 16v doesn't open below ~81-85ish so there would be no flow through the rad at 80.

Temps seem to be within limits to me but I would check for sufficient airflow through the rad. Normal driving should be more than enough to cool it down to around 80.