Eunos Roadster MK1 - injector seals replaced, engine hotter

[Eunosfan]

Hi all,

Hope you're all having a great Bank Hol.

It's been a while but I still have 'my baby' - Eunos Roadster MK1 1.6 NA.

Can I have some help please - one of the injectors developed a leak, the seals were replaced on all of them, the leak has stopped, but now she smells hot and after journeys when the engine is turned off the engine is hotter than normal and is still really hot to touch two hours later. Taking much longer to cool down. The water in the water resevoir is also getting hot. She's usually cold 30-60 mins after the engine is turned off. Am doing about 11-22 miles a day if am out atm. Longest trip has been to the garage approx 20 miles.

The coolant is correct, levels all good, the fan is working, sensors working, the temp gauge on the dash is less than half way. So have been told it's not the engine over heating as such and something is causing this.

We've also noticed when the key is in the 'on' position there is now an electrical / buzzing noise coming from the location framed in red in the photo - more to the right hand side, or it could be coming from underneath.

Could be coincidental timing ref changing the seals but this hasn't happened before. Any idea what is causing this please as will be good to get a permanent fix and have her back to normal? Don't like the idea of her being overly hot.

The mechanics have been amazing but she has flummoxed them and extra advice will be really appreciated. Am hoping it's a quick fix as not ready to part with her yet.

Having said the above she is driving fine, you wouldn't know there is an issue.

Thank you, Jo

[TameRacingDriver]

Have you tried the MX5 owners club on facebook?

[Eunosfan]

Hi am trying various forums to get help, have used PH before. Kind regards, Jo

[samoht]

Eunosfan said:

now she smells hot and after journeys when the engine is turned off the engine is hotter than normal and is still really hot to touch two hours later. Taking much longer to cool down.
...
the temp gauge on the dash is less than half way. So have been told it's not the engine over heating as such

This part is a bit hard to understand, on the one hand you say the engine is hotter than normal yet at the same time the water temp gauge is normal, which suggests it isn't. So the car's normal temp when the engine is running, but stays hotter for longer after shutting off the engine?

It's definitely possible that whoever changed the injectors knocked something in the process and perhaps broke an age-weakened wire or similar.

The one thing I can think of is, if the electric fan used to stay on after the engine was switched off to cool it, and now it doesn't, that might cause it to stay hotter longer? But I'm a bit surprised if it would ever have done that.

Only other slight possibility might be some kind of air trapped in the coolant circuit maybe?

Final possibilities are that the car's fine, and it was either running too cold before, or it's just that the weather is warmer now.

[Eunosfan]

Hi, thanx for the reply, so yes, everything appears 'normal' but while driving I am getting a hot smell, and at the end of my journey when the engine is turned off, when I go back to the car the engine is still boiling hot hours later. This started the day the injector seals were replaced. Hope this is clearer? Thank you, Jo

[starsky67]

Does the fan kick in when you stop the engine hot?

Do these cars have an auxillary water pump to circulate the water after you turn it off? If so it sounds like that might have failed (maybe a knocked wire or connector?

You should probably not just turn it off hot if that is the case as the
coolant can boil and in extreme cases you could warp the head. Idle it till it’s cool and then turn it off. If you turn it on again a couple of minutes later and the water temperature has risen then that’s probably what is happening.

[HustleRussell]

Is the engine performing the same way it did before the injector seal fix? When you turn the engine off after driving, does it stop in a way which is noticeably abrupt compared to before?

OP sorry but I do wonder if some of this is in your head, i.e. the engine always took this long to cool down and you’re only noticing it now because you’re looking for something?

The engine having been worked on may smell hot because the mechanics have been splashing a bit of coolant about and putting oily hands on everything.

Sorry to state the bleedin’ obvious but atmospheric temperature has also risen quite a lot recently.

[Matt_E_Mulsion]

Eunosfan said:

The coolant is correct, levels all good, the fan is working, sensors working, the temp gauge on the dash is less than half way. So have been told it's not the engine over heating as such and something is causing this.

I echo the comments that suggest that you may be looking for a problem that doesn't exist.

[Eunosfan]

Hi all, thank you for the replies. I have owned my car for 21 years, this has only started happening on the day the seals were replaced. The mechanics have commented on this as well and advised she is too hot. The fan is working correctly and when the engine is turned off, if I turn the key to the on position sometimes it will come back on. It's not kicking in when off. If you disconnect the sensor the fan stops, so the garage have advised this is all correct. They also suggested reaching out on forums due to how hot the engine now is. They've had her in before and did not experience this. The work was done a week ago, appreciate any spills would smell, but those are now bone dry and she is still getting overly hot. They haven't done anything with the coolant as she went in for a leaking injector.

Sorry but this is not in my head and not weather / atmospheric temperature related. Sorry to state the bleedin obvious we've had lots of hot days already this year. Last year was the hottest for donkeys and this didn't happen. I'm pretty good at looking after her and checking levels regularly and notice any changes. Due to the injectors leaking I am checking her before and after journeys, hence this was noticed the same day. I would not say she is stopping abruptly. At this stage if I left her idling til she cools down it will be over two hours, as per my orig post she has never taken this long to cool down.

Any legit advice for this issue will be appreciated.

[HustleRussell]

You’ve come off super defensive there, I don’t know how many years you’ve had it, I don’t know what your level of expertise is, my queries were ‘legit’, this is an attempt at a diagnostic process.

Good luck with it.

[Eunosfan]

I've replied using the same words you did, am giving answers, and being told it's in my head. I thought I would get some help on PH. If there is anyone who can give advice based on findings from the garage I will be back tomorrow evening. Thank you, Jo

[PositronicRay]

Have you measured the temp, a cheap IR thermometer from the bay of dreams, point it at the thermostat housing.

[starsky67]

The burning smell can only be oil, or some plastic shroud melting (either through touching something hot or an electrical issue) or something rubbing (I’m which case you’d hear it)

What does it actually smell of? Plastic is very acrid

What are the coolant and oil temperatures when it is on and then a few minimises after having been turned off?

Is it using oil or coolant and is there any smoke from the tail pipe?

More info needed really to go any further.

[steveo3002]

id go with the i.r thermometer and see whats getting hot

could there have a been a spill when doing the job and its burning off and just smelling hot? any heat shield left off after the work?

id suggest if the fan comes on and its not boiling over dropping the coolant everywhere , its not that hot

[steveo3002]

what was taken off during the work? could 2 coolant hoses been swapped ? rag stuffed into a coolant pipe and forgotten?

[GreenV8S]

What was disturbed when the work was done? If the cooling system was drained, it may have introduced an air lock.

Is the radiator cooling fan going on and off as expected? Is it blowing in the correct direction?

[njw1]

Bit of a long shot but I wonder if disturbing the injectors has affected the fuelling somehow and now the engine is running lean?

[Eunosfan]

Evening all,

Thank you for the fab replies and advice. I will try to answer everything. Sorry for the delay long day.

So there was no work done on the radiator or coolant. An injector was leaking and that's what she went in to the garage for. There was no issue with the engine getting or staying overly hot, this only came to light on the way home and when I got home. I'd already left the garage so they didn't work on anything else. She went back to the garage on Saturday and they don't know what is causing this but have advised she is too hot and staying hot for much longer.

I am still getting the hot / burning smell coming in to the car during journeys, but not all of the time. The best way for me to describe it is just a very hot engine smell. But it's strong and not what I've encountered before. I would have thought that all spilled liquids would have burned off by now? It's been 11 days since the work.

I don't know what the actual coolant or oil temperatures are sorry. No smoke from the tail pipe. Levels are all good.

No heat shields had to be removed for the work on the injectors.

Some pipes were disconnected, throttle valve, injector rail / injectors, and all put back together. I don't know the names of the pipes and would have to add photos if that helps?

The fan is working as expected, tested by the garage on Saturday.

Unfortunately when I started her this evening she was shuddering, no misfire, gauges normal, and once that settled down she drove ok. I always sit and wait for her to warm up before I set off.

The noise I mentioned is still audible. I've add videos, technical issues so only 1-2 secs long but you can hear it. Will try to add another one tomorrow.

Hope this helps. Thank you, Jo

[Eunosfan]

[steveo3002]

have a look at the plugs

almost sounds like its gone tight for some reason