MOST engines belch out ugly black smoke when in trouble. So, too, does Ivor "the engine" Callely, hissing out a selection of petulant jibes and snide accusations at his colleagues.
The embattled senator faced another inquisition yesterday as he attended the Seanad Committee on Members' Interests to answer questions about the travel and subsistence claims made from his home in West Cork.
Having just jetted in from Spain via official business in Norway, where he was busy fighting corruption, Ivor was clearly suffering from vicious jet lag.
At least, that seemed the most likely explanation for his cranky countenance as he eyeballed the row of grim-faced senators opposite him.
Ivor was clearly in no mood to be trifled with.
So he didn't take kindly to Senator Joe O'Toole's suggestion that he had used the Oireachtas expenses system to suit himself instead of abiding by the rules.
"There are too many contradictions", he sniffed grandly.
Ivor looked pained, pointing out: "In fairness, the letter of December 2007, as well as others, is quite clear. My residence is west Cork and I've retained my Dublin home."
Mr O'Toole would not be swayed: "You seem to think it's possible to claim subsistence and travel from your home in west Cork to your home in Dublin".
The discrepancy, insisted Ivor, was all down to "personal circumstances".
He enjoys the palatial surrounds of his Cork residence in Kilcrohane for much of the year, and travels to Dublin when necessary.
Last night, we got a glimpse of some of these circumstances as he hinted about his family situation:
"We would like to think that we could live happily ever after and all we can do is give it our best shot in the best interests of our family and our marriage".
To their credit, the row of inquisitors sitting opposite had the grace to look embarrassed.
Of course, Ivor's personal circumstances don't explain why he stopped making claims from his Cork residence for the last four months of 2008 and 2009.
Sensing a further volley from Mr O'Toole, Ivor blustered: "When I was in receipt of expenses I was at all times acting reasonably.
"I honestly don't think I could have been more open".
Then it turned ugly. Rounding on a stunned Mr O'Toole, he pointed out: "You're a man who claims to be an Independent".
He then hinted at the "technical issue" that could be teased out of some "misleading" information on Mr O'Toole's website.
Senator Alex White immediately jumped to Mr O'Toole's defence, snapping: "The questions go the other way don't they?"
The gloves were well and truly off, and Mr White had his fists up.
Ivor was pressed to recall the year in which his Kilcrohane residence had been put on the market.
"Since 04, '05ish," he offered, seemingly quite unsure of the details.
Nonetheless, he had no such doubts about the fact that "so often in life it's not what you do or even the way that you do it, it's the way that people might interpret it".
He was definitely less than impressed with Mr White's interpretation of his actions.
And he showed it with a furious scowl as he listened to another onslaught of questions.
"Do you not think it's strange that you were claiming an overnight allowance to stay in your family home?" mused Mr White, smiling menacingly.
Ivor sat rooted in shock, rendered mute for the first time ever.
"Did you hear the question?" Mr White inquired.
Ivor could only whisper: "The answer to the question is that I complied with the regulations."
He went on to insist he would not be bullied by the committee, even quoting the words of Francis of Assisi in his defence:
"Accept the things I can't change, the courage to change the things I can and the wisdom to know the difference," he said.
Mercifully, Chairman Moylan eventually decided Ivor had had enough, magnanimously giving him the last word.
Ivor had another gripe to get off his chest, specifically the fact that the committee sent him a letter containing €50 in expenses to facilitate his appearance at yesterday's committee meeting.
"I found it grossly insulting", sighed Ivor.
Indeed, the public might say the same about the €81,000 that he has already claimed from the public purse.